Apparatus and methods for filling teeth and root canals

ABSTRACT

A dental apparatus is disclosed. The dental apparatus can comprise a pressure wave generator to be disposed at a treatment region of a tooth. The pressure wave generator can include an opening to deliver a flowable filling material to the treatment region. The apparatus can include a reservoir for supplying the filling material to the pressure wave generator. The pressure wave generator can be configured to generate pressure waves through the treatment region to cause the filling material to substantially fill the treatment region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/315,211, filed Jun. 25, 2014, entitled “APPARATUS AND METHODS FORFILLING TEETH AND ROOT CANALS,” and this application claims the benefitof U.S. Provisional Patent Application No. 61/839,855, filed Jun. 26,2013, entitled “APPARATUS AND METHODS FOR FILLING TEETH AND ROOTCANALS;” U.S. Provisional Patent Application No. 61/866,420, filed Aug.15, 2013, entitled “APPARATUS AND METHODS FOR FILLING TEETH AND ROOTCANALS;” U.S. Provisional Patent Application No. 61/873,789, filed Sep.4, 2013, entitled “APPARATUS AND METHODS FOR FILLING TEETH AND ROOTCANALS;” U.S. Provisional Patent Application No. 61/976,699, filed Apr.8, 2014, entitled “APPARATUS AND METHODS FOR FILLING TEETH AND ROOTCANALS;” and U.S. Provisional Patent Application No. 61/982,223, filedApr. 21, 2014, entitled “APPARATUS AND METHODS FOR FILLING TEETH ANDROOT CANALS,” each of which is hereby incorporated by reference hereinin its entirety and for all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates generally to dentistry and endodontics,and to apparatus, methods, and compositions for filling teeth and rootcanals.

Description of the Related Art

In conventional dental and endodontic procedures, mechanical instrumentssuch as drills, files, brushes, etc. are used to clean unhealthymaterial from a tooth. For example, dentists often use drills tomechanically break up carious regions (e.g., cavities) in a surface ofthe tooth. Such procedures are often painful for the patient andfrequently do not remove all the diseased material. Furthermore, inconventional root canal treatments, an opening is drilled through thecrown or side of a diseased tooth, and endodontic files are insertedinto the root canal system to open the canal spaces and remove organicmaterial therein. The root canal is then filled with an obturationmaterial such as gutta percha or a flowable material, and the tooth isrestored. However, it can be challenging to ensure that the fillingmaterial fully obturates the treatment region of the tooth. Accordingly,there is a continuing need for improved dental and endodontictreatments.

SUMMARY

Various non-limiting aspects of the present disclosure will now beprovided to illustrate features of the disclosed apparatus, methods, andcompositions. Examples of apparatus, methods, and compositions forendodontic treatments are provided.

In one embodiment, a dental apparatus is disclosed. The dental apparatuscan comprise a pressure wave generator to be disposed at a treatmentregion of a tooth. The pressure wave generator can include an opening todeliver a flowable filling material to the treatment region. Theapparatus can include a reservoir for supplying the filling material tothe pressure wave generator. The pressure wave generator can beconfigured to generate pressure waves through the treatment region tocause the filling material to substantially fill the treatment region.

In another embodiment, a method of filling a treatment region of a toothis disclosed. The method can comprise supplying a flowable fillingmaterial to the treatment region. The method can include generatingpressure waves through the filling material to cause the fillingmaterial to substantially fill the treatment region.

In yet another embodiment, a dental apparatus is disclosed. Theapparatus can include a handpiece having a distal portion to bepositioned at a treatment region of a tooth and a fluid supply lineextending proximally from the distal portion. The distal portion cancomprise an opening for supplying fluid to the treatment region from thefluid supply line. The apparatus can be configured to operate in acleaning mode in which cleaning fluid passes through the opening toclean the treatment region. The apparatus can be configured to operatein a filling mode in which a flowable filling material passes throughthe opening to fill the treatment region.

In another embodiment, a dental apparatus is disclosed. The dentalapparatus can include a handpiece having a distal portion to bepositioned at a treatment region of a tooth. The handpiece can furthercomprise a first fluid supply line and a second fluid supply line todeliver fluid to the treatment region. The apparatus can be configuredto deliver a first composition through the first fluid supply line and asecond composition through the second fluid supply line to the treatmentregion. The apparatus can be further configured to combine the firstcomposition with the second composition at a location in the handpieceor at the treatment region of the tooth to form a filling material tosubstantially fill the treatment region.

In another embodiment, a method of obturating a treatment region of atooth is disclosed. The method can include supplying a first compositionto a handpiece. The method can include supplying a second composition tothe handpiece. The method can comprise forming a filling material bycombining the first composition with the second composition at alocation in the handpiece or at the treatment region of the tooth. Themethod can comprise causing the filling material to flow throughoutsubstantially the entire treatment region.

In another embodiment, a method of filling a treatment region of a toothis disclosed. The method can comprise supplying a flowable fillingmaterial to the treatment region. The method can further includeactivating a pressure wave generator to cause the flowable fillingmaterial to harden or to enhance the hardening of the flowable fillingmaterial.

In another embodiment, a dental apparatus is disclosed. The dentalapparatus can include a handpiece and a fluid supply line. The dentalapparatus can include a supply device for supplying a filling materialto the handpiece through the fluid supply line. The supply device cancomprise a coiled portion of the fluid supply line.

For purposes of this summary, certain aspects, advantages, and novelfeatures of certain disclosed inventions are summarized. It is to beunderstood that not necessarily all such advantages may be achieved inaccordance with any particular embodiment of the invention. Thus, forexample, those skilled in the art will recognize that the inventionsdisclosed herein may be embodied or carried out in a manner thatachieves one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein. Further, the foregoing is intended to summarize certaindisclosed inventions and is not intended to limit the scope of theinventions disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, aspects, and advantages of theembodiments of the apparatus and methods of cleaning teeth are describedin detail below with reference to the drawings of various embodiments,which are intended to illustrate and not to limit the embodiments of theinvention. The drawings comprise the following figures in which:

FIG. 1A is a schematic diagram of a system for cleaning a root canal ofa tooth, in accordance with the embodiments disclosed herein.

FIG. 1B is a schematic diagram of the system of FIG. 1A, in which thesystem is configured to obturate the root canal, in accordance with theembodiments disclosed herein.

FIG. 1C is a schematic diagram of a system that includes componentsconfigured to clean unhealthy or undesirable material from a treatmentregion on an exterior surface of the tooth.

FIG. 1D is a schematic diagram of the system of FIG. 1C, in which thesystem is configured to fill the cleaned treatment region, in accordancewith the embodiments disclosed herein.

FIGS. 2A and 2B are graphs that schematically illustrate possibleexamples of power that can be generated by different embodiments of apressure wave generator.

FIG. 2C is a graph of an acoustic power spectrum generated at multiplefrequencies by pressure wave generators disclosed herein.

FIG. 3A illustrates images of root canals that compare the use ofnon-degassed liquid and degassed liquid in the disclosed pressure wavegenerators.

FIG. 3B is a plot comparing the power output for techniques usingnon-degassed and degassed liquids.

FIG. 4A is a schematic side view of a tooth coupler comprising ahandpiece having a cleaning mode and an obturation or filling mode.

FIG. 4B is a schematic side cross-sectional view of the handpiece shownin FIG. 4A.

FIG. 5A is a schematic side view of a treatment handpiece configured todeliver a flowable obturation or filler material to a treatment regionof a tooth.

FIG. 5B is a schematic side cross-sectional view of the handpiece shownin FIG. 5A.

FIG. 6A is a schematic side view of a handpiece having a cleaning modeand an obturation or filling mode.

FIG. 6B is a schematic side cross-sectional view of the handpiece shownin FIG. 6A.

FIG. 6C is a side cross-sectional view of a handpiece configured tocouple to a console by way of an interface member and a cartridgeconfigured to be disposed between the interface member and the console.

FIG. 6D is a schematic, cross-sectional magnified view of a cartridgedisposed proximal a handpiece.

FIG. 7A is a schematic side view of a handpiece having a removableobturation reservoir.

FIG. 7B is a schematic side cross-sectional view of the handpiece shownin FIG. 7A.

FIG. 8A is a schematic side cross-sectional view of a handpiececonfigured to deliver a first composition and a second composition to atreatment region of a tooth to obturate or fill the treatment region,according to one embodiment.

FIG. 8B is a schematic side cross-sectional view of a handpiececonfigured to deliver a first composition and a second composition tofill a treatment region of a tooth, according to another embodiment.

FIG. 8C is a schematic side cross-sectional view of a handpiececonfigured to deliver multiple components of an obturation material tothe treatment region, according to one embodiment.

FIG. 8D is a schematic side cross-sectional view of a handpiececonfigured to deliver multiple components of an obturation material tothe treatment region, according to another embodiment.

FIG. 9A is a photograph illustrating a cross-sectional view of anobturated root canal that was filled in a procedure in accordance withvarious embodiments disclosed herein.

FIG. 9B is a scanning electron micrograph of a split, obturated rootthat was filled in the procedure of FIG. 9A.

Throughout the drawings, reference numbers may be re-used to indicate ageneral correspondence between referenced elements. The drawings areprovided to illustrate example embodiments described herein and are notintended to limit the scope of the disclosure.

DETAILED DESCRIPTION I. Overview of System and Methods A. Overview ofVarious System Components

FIG. 1A is a schematic diagram of a system 1, in accordance with theembodiments disclosed herein. The system 1 shown in FIG. 1A may beconfigured to perform various types of treatment procedures, including,e.g., cleaning treatments, obturation treatments, restorationtreatments, etc. In the embodiment shown in FIG. 1A, the system 1 isillustrated as being coupled to (e.g., positioned against in somearrangements) a tooth 10 that is a molar tooth of a mammal, such as ahuman. However, the tooth 10 may be any other suitable type of tooth,such as a pre-molar, bicuspid, incisor, canine, etc. Furthermore, thesystem 1 shown in FIG. 1A can include components configured to removeunhealthy or undesirable materials from a tooth or surrounding gumtissue, for example, a root canal 13 of the tooth 10. Thus, in theembodiment of FIG. 1A, the system 10 is configured to clean the tooth10.

The tooth 10 includes hard structural and protective layers, including ahard layer of dentin 16 and a very hard outer layer of enamel 17. A pulpcavity 11 is defined within the dentin 16. The pulp cavity 11 comprisesone or more root canals 13 extending toward an apex 14 of each root 12.The pulp cavity 11 and root canal 13 contain dental pulp, which is asoft, vascular tissue comprising nerves, blood vessels, connectivetissue, odontoblasts, and other tissue and cellular components. Bloodvessels and nerves enter/exit the root canal 13 through a tiny opening,the apical foramen or apical opening 15, near a tip of the apex 14 ofthe root 12. It should be appreciated that, although the tooth 10illustrated herein is a molar, the embodiments disclosed herein canadvantageously be used to treat any suitable type of tooth, includingpre-molars, canines, incisors, etc.

As illustrated in FIG. 1A, the system 1 can be used to remove unhealthymaterials (such as organic and inorganic matter) from an interior of thetooth 10, e.g., from the root canal 13 of the tooth 10. For example, anendodontic access opening 18 can be formed in the tooth 10, e.g., on anocclusal surface, a buccal surface, or a lingual surface. The accessopening 18 provides access to a portion of a pulp cavity 11 of the tooth10. The system 1 can include a console 2, a pressure wave generator 5,and a tooth coupler 3 (such as a handpiece) adapted to couple to thetooth 10. The tooth coupler 3 can couple to the tooth 10 in any suitableway. In some arrangements, the tooth coupler 3 can be positioned againstand/or attach to the tooth 10 by way of a tooth seal 75. For example,the clinician can hold the tooth coupler 3 against the tooth 10 duringtreatment. In some embodiments, the tooth coupler 3 can define a chamber6 configured to retain fluid therein. In some embodiments, the pulpcavity 11 can define a tooth chamber configured to retain fluid therein.In some embodiments, the tooth coupler 3 may not define a chamber, andthe tooth chamber defined at least in part by the pulp cavity 11 canretain fluid.

The tooth coupler 3 disclosed herein can be any suitable structure orhousing configured to couple to the tooth 10 for a treatment procedure.As used herein, “couple” is meant to include arrangements in which thereis a connection with the tooth 10, as well as arrangements in which thecoupler 3 is placed against or in the tooth and is held by the clinicianin that position. The pressure wave generator 5 can be coupled to and/ordisposed in or on the tooth coupler 3 in various embodiments.

A system interface member 4 can electrically, mechanically, and/orfluidly connect the console 2 with the tooth coupler 3 and pressure wavegenerator 5. For example, in some embodiments, the system interfacemember 4 can removably couple the tooth coupler 3 to the console 2. Insuch embodiments, the clinician may use the tooth coupler 3 one time (ora few times), and may dispose the tooth coupler 3 after each procedure(or after a set number of procedures). The console 2 and interfacemember 4 may be reused multiple times to removably couple (e.g., toconnect and/or disconnect) to multiple tooth couplers 3 using suitableengagement features, as discussed herein. The interface member 4 caninclude various electrical and/or fluidic pathways to provideelectrical, electronic, and/or fluidic communication between the console2 and the tooth coupler 3. The console 2 can include a control systemand various fluid and/or electrical systems configured to operate thepressure wave generator 5 during a treatment procedure. The console 2can also include a management module configured to manage data regardingthe treatment procedure. The console 2 can include a communicationsmodule configured to communicate with external entities about thetreatment procedures.

As shown in FIG. 1A, the system 1 can be used in cleaning procedures toclean substantially the entire root canal system. In other procedures,such as obturation procedures (see FIG. 1B), the system 1 can be used tofill substantially the entire root canal system with an obturation orfiller material. In still other procedures, the system 1 can be used torestore a tooth 10. For example, in cleaning procedures, the chamber 6of the tooth coupler 3 and/or the pulp cavity 11 of the tooth 10 can beat least partially (or substantially) filled with a fluid 22. In variousembodiments disclosed herein, the pressure wave generator 5 can generatepressure waves 23 that propagate through the fluid 22. The generatedpressure waves 23 may be of sufficient power and relatively lowfrequencies to produce fluid motion 24 in the pulp cavity 11 of thetooth 10, the root canal 13, and/or in the chamber 6 of the toothcoupler 3. The pressure wave generator 5 can also generate pressurewaves of sufficient power and relatively higher frequencies to producesurface effect cavitation and/or microscale fluid motion created by theimpact of the waves on a surface, either inside or outside the tooth 10.That is, for example, the pressure wave generators 5 disclosed hereincan clean the tooth by generating large-scale or bulk fluid motion 24 inor near the tooth 10, and by generating smaller-scale fluid motion athigher frequencies. In some arrangements, the fluid motion 24 in thechamber 6 can generate induced fluid motion such as vortices 74, swirl,etc. in the tooth 10 and root canal 13 that can clean the canal 13. Forexample, in some embodiments, a high velocity stream of liquid can passover an orifice (such as the canals), which can create a high speedstream of liquid transverse to the canals. The transverse stream mayinduce vortices 74 that traverse down the canals 13. Thus, thehigh-pressure stream can create a low pressure stream that cleans theroot canals. In some arrangements, the pressure waves 23 can generatenormal stress or shear stress or a combination of both onto the surfaceswithin the treatment region. Although the pressure wave generator 5shown in FIG. 1A is shown as extending into the tooth, in otherarrangements, the pressure wave generator 5 may be disposed outside thetooth, such as within the chamber 6. Additional systems and methods forcleaning teeth, e.g., using pressure wave generators that can include aliquid jet device, (including molars, pre-molars, etc.) may be found inU.S. Patent Publication US 2007/0248932, in U.S. Patent Publication2011/0117517, in U.S. Patent Publication US 2012/0237893 and in U.S.patent application Ser. No. 14/137,937, filed Dec. 20, 2013, titled“APPARATUS AND METHODS FOR CLEANING TEETH AND ROOT CANALS,” each ofwhich is incorporated by reference herein in its entirety and for allpurposes. Additionally, the console 2 can include a control systemcomprising a processor and non-transitory memory. Computer-implementedinstructions can be stored on the memory and can be executed by theprocessor to assist in controlling cleaning and/or filling procedures.Additional details of the console 2 may be found in U.S. patentapplication Ser. No. 14/172,809, filed on Feb. 4, 2014, entitled “DENTALTREATMENT SYSTEM,” and in U.S. Patent Publication No. US 2012/0237893,each of which is incorporated by reference herein in its entirety andfor all purposes.

FIG. 1B is a schematic diagram of the system 1, in which the system isconfigured to obturate or fill the root canals 13 of the tooth 10. Aswith the embodiment of FIG. 1A, the system can include a pressure wavegenerator 5, a tooth coupler 3, an interface member 4, and a console 2.In FIG. 1B, the system 1 is used to fill or obturate the root canal 13with an obturation material 45. For example, the clinician can clean theroot canal 13 in any suitable way, such as by using drills or files, orby using a pressure wave generator (which may be the same as ordifferent from the pressure wave generator 5 shown in FIG. 1B). When theroot canal 13 is cleaned, the clinician can supply an obturationmaterial 45 in its flowable state to the pulp cavity 11, canals 13, orother internal chambers of the tooth 10.

As explained herein, the clinician can supply the obturation material 45to the treatment region (e.g., the root canal) in any suitable manner.For example, in some embodiments, the pressure wave generator 5 (whichmay be coupled to or formed with a handpiece) may have one or moreopenings (see, e.g., FIGS. 4A-4B, et seq.) configured to deliver theflowable obturation material 45 to the tooth 10. In other embodiments,the clinician can supply the obturation material 45 to the tooth bymanually placing it in the tooth 10, e.g., by hand, by syringe, or by amechanical tool. In still other embodiments, a dental handpiece caninclude one or more supply lines that are configured to route theflowable obturation material 45 to the tooth 10. The obturation material45 can be any suitable obturation material disclosed herein. Inparticular, the obturation material 45 can have a flowable state inwhich the obturation material 45 flows through the treatment region tofill the root canals 13 and/or pulp cavity 11. The obturation material45 can have a hardened state in which the obturation material 45solidifies after filling the treatment region.

Advantageously, the pressure wave generator 5 can be activated toenhance the obturation procedure. For example, the pressure wavegenerator 5 can be activated to assist in flowing the obturationmaterial 45 throughout the treatment region to be filled. The pressurewave generator 45 can thereby assist in substantially filling the tooth10. As shown in inset 50 of FIG. 1B, for example, when activated, thepressure wave generator 5 can cause the obturation material 45 to flowinto major canal spaces 51 of the tooth 10, as well as into small spaces53 of the tooth 10. Thus, the system 1 shown in FIG. 1B can assist infilling even small cracks, tubules, and other tiny spaces (e.g., thesmall spaces 53) of the tooth 10. By filling the small spaces 53 of thetooth, the system 1 can ensure a more robust obturation procedure whichresults in long-term health benefits for the patient. As explainedherein, the pressure waves 23 and/or fluid motion 24 (which may includevortices 74) generated by the pressure wave generator 5 may interactwith the obturation material 45 to assist in filling the small spaces 53and the major spaces 51 of the tooth 10. Furthermore, in someembodiments, the pressure wave generator 5 can be activated to assist incuring or hardening the obturation material 45. For example, asexplained herein, some types of obturation materials may cure or harden(or the curing or hardening may be enhanced) when agitated by pressurewaves 23 generated by the pressure wave generator 5. In addition, invarious embodiments, the obturation or filling material can be degassed,which can help deliver the obturation material to small spaces of thetooth. Accordingly, the pressure wave generator 5 can enhance theobturation procedure in a variety of ways.

In some embodiments, the obturation material 45 is supplied to the tooth10, and the pressure wave generator 5 is subsequently activated toenhance the obturation procedure (e.g., to improve the filling processand/or to enhance or activate the curing process). For example, in suchembodiments, the clinician can supply the obturation material 45 to thetooth 10 using a syringe or other device, and the pressure wavegenerator 5 can subsequently (or concurrently) be activated to fill thetreatment region. In other embodiments, the pressure wave generator 5can supply the obturation material 45 and generate pressure wavesthrough the obturation material (or other fluids at the treatmentregion). In some embodiments, supplying the obturation material andgenerating pressure waves can occur substantially simultaneously, or canoverlap by some amount over time. For example, the pressure wavegenerator 5 can be activated to supply the obturation material 45 to thetreatment region. For example, in embodiments in which the pressure wavegenerator 5 comprises a liquid jet, a jet of obturation material 45 caninteract with fluids in the tooth 10 (e.g., other portions of theobturation material or other treatment fluid) to generate pressure wavesthat propagates through the fluids. The resulting pressure waves canenhance the obturation procedure. In other embodiments, different typesof fluids (e.g., water or other treatment fluids) may form the jet, andthe jet can pass through obturation materials in the treatment region.Interaction of the fluid jet and the obturation material can enhance theobturation procedure.

As disclosed herein, the pressure wave generator 5 can comprise anysuitable type of pressure wave generator, e.g., a liquid jet device, alaser, a mechanical stirrer, an ultrasonic transducer, etc. The pressurewave generator 5 can be sized such that the pressure wave generator 5 isdisposed outside the region of the tooth 10 that is to be obturated. Forexample, the pressure wave generator 5 can be disposed in the chamber 6such that it is disposed outside the tooth 10. In other arrangements,the pressure wave generator 5 can extend partially into the tooth 10. Insome arrangements, the pressure wave generator 5 can extend to a depththat does not interfere with the filling. As explained herein, thesystem 1 can include a cleaning mode for cleaning the treatment regionand a filling mode to fill or obturate the treatment region. The console2 can include a control system comprising a processor and memory. Thecontrol system can be programmed or configured to switch the system 1from the cleaning mode to the filling mode and vice versa. The controlsystem of the console 2 can also control the operation of cleaningand/or filling procedures.

FIG. 1C is a schematic diagram of a system 1 that includes componentsconfigured to clean unhealthy or undesirable material from a treatmentregion 20 on an exterior surface of the tooth 10. For example, as inFIG. 1A, the system 1 can include a tooth coupler 3 and a pressure wavegenerator 5. The tooth coupler 3 can communicate with a console 2 by waya system interface member 4. Unlike the system 1 of FIG. 1A, however,the tooth coupler 3 is coupled to (e.g., positioned against by aclinician) a treatment region 20 on an exterior surface of the tooth 10.In some embodiments, the tooth coupler 3 can be stably positionedagainst the treatment region and can be sealed to the tooth 10, e.g., byway of an adhesive or other seal. The system 1 of FIG. 1C can beactivated to clean an exterior surface of the tooth 10, e.g., a cariousregion of the tooth 10 and/or remove undesirable dental deposits, suchas plaque, calculus biofilms, bacteria, etc, from the tooth 10 and/orsurround gum tissue. In other embodiments (see FIG. 1D), the system 1can be activated to fill a treated region on the exterior surface of thetooth 10 with a filling or restoration material. As with the embodimentof FIG. 1A, pressure waves 23 and/or fluid motion 24 can be generated inthe tooth coupler 3 and chamber 6, which can act to clean the treatmentregion 20 of the tooth 10, forming a cleaned treatment region 20A inwhich the carious (or other unhealthy material) is removed. Additionaldetails of systems and methods for treating carious regions of teeth maybe found in International Application Publication WO 2013/142385(PCT/US2013/032635), having an international filing date of Mar. 15,2013, entitled “APPARATUS AND METHODS FOR CLEANING TEETH,” which isincorporated by reference herein in its entirety and for all purposes.Additional details of systems and methods for removing undesirabledental deposits (such as plaque, calculus, etc.) from teeth and/or gumsmay be found in International Application Publication WO 2013/155492(Application No. PCT/US2013/036493), having an international filing dateof Apr. 12, 2013, entitled “APPARATUS AND METHODS FOR CLEANING TEETH ANDGINGIVAL POCKETS,” and in U.S. Patent Publication No. US 2014/0099597,filed Apr. 11, 2013, entitled “APPARATUS AND METHODS FOR CLEANING TEETHAND GINGIVAL POCKETS,” each of which is incorporated by reference hereinin its entirety and for all purposes.

FIG. 1D is a schematic diagram of the system 1 of FIG. 1C, in which thesystem 1 is configured to fill the treated carious region 20A of thetooth 10. As with the embodiment of FIG. 1C, the system can include apressure wave generator 5, a tooth coupler 3, an interface member 4, anda console 2. When the carious or other unhealthy material is removedfrom the tooth 10, the clinician can fill the cleaned treatment region20A with a suitable filler or obturation material 45. As with theembodiment of FIG. 1B, the obturation material 45 can be supplied to thecleaned treatment region 20A. The pressure wave generator 5 can act tosubstantially fill the treatment region 20A and/or to enhance oractivate the hardening of the filler obturation material 45. In someembodiments, the filler or obturation material 45 is supplied to thetooth 10, and the pressure wave generator 5 is subsequently activated toenhance the filling procedure (e.g., to improve the filling processand/or to enhance or activate the curing process). For example, in suchembodiments, the clinician can supply the filler or obturation material45 to the treatment region 20A using a syringe, and the pressure wavegenerator 5 can subsequently be activated to fill the treatment region.In other embodiments, the pressure wave generator 5 is activated tosupply the filler or obturation material 45 to the treatment region 20Aand to generate pressure waves through the material. For example, inembodiments in which the pressure wave generator 5 comprises a liquidjet, a jet of obturation or filler material 45 (or other type of fluid)can interact with fluids at the treatment region 20A (e.g., otherportions of the filler or obturation material or other treatment fluid)to generate pressure waves that propagates through the fluids. Theresulting pressure waves can enhance the obturation procedure.

B. Overview of Treatment Procedures

The system 1 disclosed herein can be used with various types oftreatment procedures. For example, some embodiments disclosed herein canadvantageously remove undesirable or unhealthy materials from a toothsuch that substantially all the unhealthy material is removed whileinducing minimal or no discomfort and/or pain in the patient. Forexample, when activated by the clinician, the pressure wave generator 5can induce various fluidic effects that interact with the unhealthymaterial to be removed, even when the pressure wave generator 5 isdisposed at a position remote from the treatment region of the tooth,e.g., the region of the tooth that includes the unhealthy or undesirablematerial to be removed. The pressure wave generator 5 can impart energyto a fluid 22 that induces the relatively large-scale or bulkcirculation or movement 24 of liquid in the chamber 6 and/or tooth 10,and that also generates pressure waves 23 that propagate through thefluid 22 and tooth 10. The generated fluid motion 24 and pressure waves23 can magnify or enhance the properties of the fluid 22 to enhancecleaning of the tooth 10. In some embodiments, the pressure wavegenerator 5 can be used to obturate or fill the root canals and/or othertreated regions of the tooth, and can also be used to restore or buildup a damaged or diseased tooth.

1. Enhancing the Cleaning of Teeth

The system 1 disclosed herein can be used to clean teeth. For example,the system 1 can be configured to clean organic and inorganic material,including diseased pulp, bacteria, etc., from root canals of the tooth10. In some embodiments, the system 1 can be configured to removecarious regions of the tooth 10, e.g., regions of the tooth 10 that aredecayed. The carious regions can be formed on an exterior surface of thetooth 10 in some arrangements. Moreover, the system 1 can be configuredto clean undesirable dental deposits from exterior surfaces of the tooth10, including plaque, calculus, biofilms, bacteria, and other unhealthydeposits. In some arrangements, the system 1 can utilize, alone or incombination, the chemistry of various treatment fluids, pressure wavesgenerated by the pressure wave generator 5, and fluid motion 24 createdin the chamber 6 of the tooth coupler 3 and/or in a chamber within thetooth 10.

a. Chemistry of Various Treatment Fluids

In cleaning procedures, the fluid 22 supplied to the chamber 6 and/or tothe pulp cavity 11 of the tooth 10 can comprise a treatment fluid thatcan be introduced into the tooth 10 and the chamber 6 to assist inremoving unhealthy or undesirable materials from the tooth 10. Thetreatment fluids can be selected based on the chemical properties of thefluids when reacting with the undesirable or unhealthy material to beremoved from the tooth 10. The treatment fluids disclosed herein caninclude any suitable fluid, including, e.g., water, saline, etc. Variouschemicals can be added to treatment fluid for various purposes,including, e.g., tissue dissolving agents (e.g., NaOCl or bleach),disinfectants (e.g., chlorhexidine), anesthesia, fluoride therapyagents, ethylenediaminetetraacetic acid (EDTA), citric acid, and anyother suitable chemicals. For example, any other antibacterial,decalcifying, disinfecting, mineralizing, or whitening solutions may beused as well. The clinician can supply the various fluids to the toothin one or more treatment cycles, and can supply different fluidssequentially or simultaneously.

During some treatment cycles, bleach-based solutions (e.g., solutionsincluding NaOCl) can be used to dissociate diseased tissue (e.g.,diseased organic matter in the root canal 13) and/or to remove bacteria,biofilm or endotoxins (Lipopolysaccharide or LPS) from the tooth 10. Oneexample of a treatment solution comprises water or saline with 0.3% to6% bleach (NaOCl). In some methods, tissue dissolution and dentaldeposit removal in the presence of bleach may not occur when the bleachconcentration is less than 1%. In some treatment methods disclosedherein, tissue dissolution and dental deposit removal can occur atsmaller (or much smaller) concentrations.

During other treatment cycles, the clinician can supply an EDTA-basedsolution to remove undesirable or unhealthy calcified material from thetooth 10. For example, if a portion of the tooth 10 and/or root canal 13is shaped or otherwise instrumented during the procedure, a smear layermay form on the walls of the canal 13. The smear layer can include asemi-crystalline layer of debris, which may include remnants of pulp,bacteria, dentin, and other materials. Treatment fluids that includeEDTA may be used to remove part or all of the smear layer, and/orcalcified deposits on the tooth 10. EDTA may also be used to removedentin packed into isthmuses and lateral canals during theinstrumentation process. EDTA may also be used to remove a microscopiclayer off enamel and cleaning and staining purposes. Other chemicalssuch as citric acid may also be used for similar purposes.

During yet other cycles, for example, the clinician may supply atreatment fluid that comprises substantially water. The water can beused to assist in irrigating the tooth before, during, and/or after thetreatment. For example, the water can be supplied to remove remnants ofother treatment fluids (e.g., bleach or EDTA) between treatment cycles.Because bleach has a pH that tends to be a base and because EDTA is anacid, it can be important to purge the tooth 10 and chamber 6 betweenbleach and EDTA treatments to avoid potentially damaging chemicalreactions. Furthermore, the water can be supplied with a sufficientmomentum to help remove detached materials that are disrupted during thetreatment. For example, the water can be used to convey waste materialfrom the tooth 10.

Various solutions may be used in combination at the same time orsequentially at suitable concentrations. In some embodiments, chemicalsand the concentrations of the chemicals can be varied throughout theprocedure by the clinician and/or by the system to improve patientoutcomes. For example, during an example treatment procedure, theclinician can alternate between the use of water, bleach, and EDTA, inorder to achieve the advantages associated with each of these chemicals.In one example, the clinician may begin with a water cycle to clean outany initial debris, then proceed with a bleach cycle to dissociatediseased tissue and bacteria from the tooth. A water cycle may then beused to remove the bleach and any remaining detached materials from thetooth 10. The clinician may then supply EDTA to the tooth to removecalcified deposits and/or portions of a smear layer from the tooth 10.Water can then be supplied to remove the EDTA and any remaining detachedmaterial from the tooth 10 before a subsequent bleach cycle. Theclinician can continually shift between cycles of treatment fluidthroughout the procedure. The above example is for illustrative purposesonly. It should be appreciated that the order of the cycling oftreatment liquids may vary in any suitable manner and order.

Thus, the treatment fluids used in the embodiments disclosed herein canreact chemically with the undesirable or unhealthy materials todissociate the unhealthy materials from the healthy portions of thetooth 10. The treatment fluids can also be used to irrigate waste fluidand/or detached or delaminated materials out of the tooth 10. In someembodiments, as explained in more detail herein, the treatment solution(including any suitable composition) can be degassed, which may improvecavitation and/or reduce the presence of gas bubbles in some treatments.In some embodiments, the dissolved gas content can be less than about 1%by volume.

b. Enhancement of Cleaning and Filling Using Pressure Waves and Examplesof Pressure Wave Generators

A pressure wave generator 5 can remove unhealthy materials from a toothby propagating pressure waves 23 through a propagation medium such asthe fluid 22 (e.g., the treatment fluid) to the treatment region, whichcan include one or more teeth and/or gums. Without being limited bytheory, a few potential ways that the pressure waves 23 removeundesirable materials are presented herein. In addition, the pressurewave generators disclosed herein may also be used to effectivelyobturate or fill treatment regions of the tooth. Note that theseprinciples, and the principles described above, may be generallyapplicable for each embodiment disclosed herein.

In some arrangements, cavitation may be induced by the generatedpressure waves 23. Upon irradiation of a liquid (e.g., water or othertreatment fluid) with high intensity pressure or pressure waves 23,acoustic cavitation may occur. The oscillation or the implosive collapseof small cavitation bubbles can produce localized effects, which mayfurther enhance the cleaning process, e.g., by creating intense,small-scale localized heat, shock waves, and/or microjets and shearflows. Therefore, in some treatment methods, acoustic cavitation may beresponsible for or involved in enhancing the chemical reactions,sonochemistry, sonoporation, soft tissue/cell/bacteria dissociation,delamination and breakup of biofilms.

For example, if the treatment liquid contains chemical(s) that act on aparticular target material (e.g., diseased organic or inorganic matter,stains, caries, dental calculus, plaque, bacteria, biofilms, etc.), thepressure waves 23 (acoustic field) and/or the subsequent acousticcavitation may enhance the chemical reaction via convection, turbulence,agitation and/or sonochemistry. Indeed, the pressure waves 23 canenhance the chemical effects that each composition has on the unhealthymaterial to be removed from the tooth. For example, with a bleach-basedtreatment fluid, the generated pressure waves 23 can propagate so as todissociate tissue throughout the entire tooth 10, including in thedentinal tubules and throughout tiny cracks and crevices of the tooth10. As another example, with an EDTA-based treatment fluid, thegenerated pressure waves 23 can propagate so as to remove the smearlayer and/or calcified deposits from the tooth 10, including in thetubules and/or in tiny cracks and crevices formed in the tooth 10. Witha water-based treatment fluid, the generated pressure waves 23 canpropagate so as to flush and/or irrigate undesirable materials from thetooth, including in tubules and tiny cracks and crevices. Accordingly,the generated pressure waves 23 can enhance the removal of undesirableor unhealthy materials from the tooth 10 by magnifying the chemicaleffects of whatever treatment fluid composition is used during aparticular treatment cycle.

Furthermore, sonoporation, which is the process of using pressure wavesand/or the subsequent acoustic cavitation to modify the permeability ofthe bacterial cell plasma membrane, may also expedite the chemicalreaction that removes the microorganisms from the tooth. It should alsobe appreciated that generated pressure waves, and/or the subsequentacoustic cavitation of certain frequencies, may result in cellular andbacterial rupture and death (e.g., lysis) as well as removal of decayedand weakened dentin and enamel. The cellular and bacterial rupturephenomenon may kill bacteria which might otherwise reinfect the gingivalpockets and/or the oral cavity.

Generated pressure waves and/or the subsequent acoustic cavitation mayalso loosen the bond of the structure of the unhealthy material (e.g.,diseased tissue, calculus, biofilm, caries, etc.), and/or the pressurewaves may dissociate the unhealthy material from the tooth 10. In somecases, pressure waves and/or acoustic cavitation may loosen the bondbetween the cells and the dentin and/or delaminate the tissue from thetooth. Furthermore, the pressure waves and/or the subsequent acousticcavitation may act on decayed hard tissue (which may be relatively weakand loosely connected) through vibrations and/or shock waves, and/or themicrojets created as a result of cavitation bubble implosion, to removedecayed hard tissue from other healthy portions of the tooth.

A pressure wave generator 5 can be used in various disclosed embodimentsto clean a tooth 10, e.g., from interior or exterior portions of thetooth 10 and/or gums. In other embodiments, the pressure wave generator5 can be used to fill or obturate a cleaned root canal or othertreatment region of the tooth 10. In some embodiments, the pressure wavegenerator 5 can comprise an elongated member having an active distal endportion. The active distal end portion can be activated by a user toapply energy to the treatment tooth 10 to remove unhealthy orundesirable material from the tooth 10.

As explained herein, the disclosed pressure wave generators 5 can beconfigured to generate pressure waves 23 and fluid motion 24 with energysufficient to clean undesirable material from a tooth 10. The pressurewave generator 5 can be a device that converts one form of energy intoacoustic waves and bulk fluid motion (e.g., rotational motion) withinthe fluid 22. The pressure wave generator 5 can induce, among otherphenomena, both pressure waves and bulk fluid dynamic motion in thefluid 22 (e.g., in the chamber 6), fluid circulation, turbulence,vortices and other conditions that can enable the cleaning of the tooth.The pressure wave generator 5 disclosed in each of the figures describedherein may be any suitable type of pressure wave generator.

The pressure wave generator 5 can be used to clean the tooth 10 bycreating pressure waves that propagate through the fluid 22, e.g.,through treatment fluid at least partially retained in the chamber 6. Insome implementations, the pressure wave generator 5 may also createcavitation, acoustic streaming, turbulence, etc. The pressure wavegenerator 5 (e.g., high-speed liquid jet, ultrasonic transducer, a laserfiber, etc.) can be placed at the desired treatment location in or onthe tooth 10. The pressure wave generator 5 can create pressure waves 23and fluid motion 24 within the fluid 22 inside a substantially-enclosedchamber 6 and/or in a tooth chamber of the tooth (e.g., the pulp cavity11 and/or the root canal 13). In general, the pressure wave generator 5can be sufficiently strong to remove unhealthy materials such as organicand/or inorganic tissue from teeth 10. In some embodiments, the pressurewave generator 5 can be configured to avoid substantially breaking downor harming natural dentin and/or enamel.

i. Liquid Jet Apparatus

For example, in some embodiments, the pressure wave generator 5 cancomprise a liquid jet device. The liquid jet can be created by passinghigh pressure liquid through an orifice. The liquid jet can createpressure waves within the treatment liquid. In some embodiments, thepressure wave generator 5 comprises a coherent, collimated jet ofliquid. The jet of liquid can interact with liquid in asubstantially-enclosed volume (e.g., the chamber 6, the tooth chamber(e.g., pulp cavity 11 and/or root canals 13), and/or the mouth of theuser) and/or an impingement member to create the acoustic waves. Inaddition, the interaction of the jet and the treatment fluid, as well asthe interaction of the spray which results from hitting the impingementmember and the treatment fluid, may assist in creating cavitation and/orother acoustic and fluid motion effects to clean the tooth. The liquidjet apparatus can be configured to clean and/or fill or obturate atreatment region of the tooth.

In various embodiments, the liquid jet device can comprise a positioningmember (e.g., a guide tube) having a channel or lumen along which orthrough which a liquid jet can propagate. The distal end portion of thepositioning member can include one or more openings that permit thedeflected liquid to exit the positioning member and interact with thesurrounding environment in the chamber 6 and/or tooth 10. In sometreatment methods, the openings disposed at or near the distal endportion of the positioning member can be submerged in liquid that can beat least partially enclosed in the tooth coupler 3 attached to orenclosing a portion of the tooth 10. In some embodiments, the liquid jetcan pass through the guide tube and can impact an impingement surface.The passage of the jet through the surrounding treatment fluid andimpact of the jet on the impingement surface can generate the acousticwaves in some implementations. The flow of the submerged portion of theliquid jet may generate a cavitation cloud within the treatment fluid.The creation and collapse of the cavitation cloud may, in some cases,generate a substantial hydroacoustic field in or near the tooth. Furthercavitation effects may be possible, including growth, oscillation, andcollapse of cavitation bubbles. In addition, as explained above, bulkfluid motion, such as rotational flow, may be induced. The inducedrotational flow can enhance the cleaning process by removing detachedmaterial and replenishing reactants for the cleaning reactions. These(and/or other) effects may lead to efficient cleaning of the tooth. Therotational flow may also create sufficient shear stress onto surfacewhich then leads to dissociation, detachment, and delamination ofunhealthy materials. In some embodiments, the rotational flow mayinclude turbulent regions working on small scale regions or small scaleunhealthy materials.

Additional details of a pressure wave generator and/or pressure wavegenerator that includes a liquid jet device may be found at least in ¶¶[0045]-[0050], [0054]-[0077] and various other portions of U.S. PatentPublication No. US 2011/0117517, published May 19, 2011, and in ¶¶[0136]-[0142] and various other portions of U.S. Patent Publication No.US 2012/0237893, published Sep. 20, 2012, each of which is incorporatedby reference herein in its entirety and for all purposes.

As has been described, a pressure wave generator can be any physicaldevice or phenomenon that converts one form of energy into acousticwaves within the treatment fluid and that induces normal and shearstresses as well as small scale flows near a treatment region in thechamber 6 and/or tooth 10. The pressure wave generator 5 may alsoconvert the energy into rotational fluid motion of various length scalesin the chamber 6 and/or tooth 10. Many different types of pressure wavegenerators (or combinations of pressure wave generators) are usable withembodiments of the systems and methods disclosed herein.

ii. Mechanical Energy

Mechanical energy pressure wave generators can also include rotatingobjects, e.g. miniature propellers, eccentrically-confined rotatingcylinders, a perforated rotating disk, etc. These types of pressure wavegenerators can also include vibrating, oscillating, or pulsating objectssuch as sonication devices that create pressure waves viapiezoelectricity, magnetostriction, etc. In some pressure wavegenerators, electric energy transferred to a piezoelectric transducercan produce acoustic waves in the treatment fluid. In some cases, thepiezoelectric transducer can be used to create acoustic waves having abroad band of frequencies. Mechanical pressure wave generators can beconfigured to clean and/or fill or obturate a treatment region of thetooth.

iii. Electromagnetic Energy

Electromagnetic pressure wave generators can also be configured to cleanand/or fill or obturate a treatment region of the tooth. Anelectromagnetic beam of radiation (e.g., a laser beam) can propagateenergy into a chamber, and the electromagnetic beam energy can betransformed into acoustic waves as it enters the treatment fluid. Insome embodiments, the laser beam can be directed into the chamber 6and/or tooth coupler 3 as a collimated and coherent beam of light. Thecollimated laser beam can be sufficient to generate pressure waves asthe laser beam delivers energy to the fluid. Furthermore, in variousembodiments, the laser beam can be focused using one or more lenses orother focusing devices to concentrate the optical energy at a locationin the treatment fluid. The concentrated energy can be transformed intopressure waves sufficient to clean the undesirable materials. In oneembodiment, the wavelength of the laser beam or electromagnetic sourcecan be selected to be highly absorbable by the treatment fluid in thechamber, tooth, and/or mouth (e.g., water) and/or by the additives inthe treatment fluid (e.g., nanoparticles, etc.). The electromagneticenergy can be absorbed by at least one component and can turn theelectromagnetic energy into either heat, vibration, or pressure waves,for example, through cavitation. For example, at least some of theelectromagnetic energy may be absorbed by the fluid (e.g., water) in thechamber, which can generate localized heating and pressure waves thatpropagate in the fluid. The pressure waves generated by theelectromagnetic beam can generate light-induced cavitation effects inthe fluid. In some embodiments, the localized heating can inducerotational fluid flow in the chamber 6 and/or tooth 10 that furtherenhances cleaning of the tooth 10. The electromagnetic radiation from aradiation source (e.g., a laser) can be propagated to the chamber by anoptical waveguide (e.g., an optical fiber), and dispersed into the fluidat a distal end of the waveguide (e.g., a shaped tip of the fiber, e.g.,a conically-shaped tip). In other implementations, the radiation can bedirected to the chamber by a beam scanning system.

The wavelength of the electromagnetic energy may be in a range that isstrongly absorbed by water molecules. The wavelength may in a range fromabout 300 nm to about 3000 nm. In some embodiments, the wavelength is ina range from about 400 nm to about 700 nm, about 700 nm to about 1000 nm(e.g., 790 nm, 810 nm, 940 nm, or 980 nm), in a range from about 1micron to about 3 microns (e.g., about 2.7 microns or 2.9 microns), orin a range from about 3 microns to about 30 microns (e.g., 9.4 micronsor 10.6 microns). The electromagnetic energy can be in the ultraviolet,visible, near-infrared, mid-infrared, microwave, or longer wavelengths.

The electromagnetic energy can be pulsed or modulated (e.g., via apulsed laser), for example with a repetition rate in a range from about1 Hz to about 500 kHz. The pulse energy can be in a range from about 1mJ to about 1000 mJ. The pulse width can be in a range from about 1 μsto about 500 μs, about 1 ms to about 500 ms, or some other range. Insome cases, nanosecond pulsed lasers can be used with pulse rates in arange from about 100 ns to about 500 ns. The foregoing are non-limitingexamples of radiation parameters, and other repetition rates, pulsewidths, pulse energies, etc. can be used in other embodiments.

The laser can include one or more of a diode laser, a solid state laser,a fiber laser, an Er:YAG laser, an Er:YSGG laser, an Er,Cr:YAG laser, anEr,Cr:YSGG laser, a Ho:YAG laser, a Nd:YAG laser, a CTE:YAG laser, a CO₂laser, or a Ti:Sapphire laser. In other embodiments, the source ofelectromagnetic radiation can include one or more light emitting diodes(LEDs). The electromagnetic radiation can be used to excitenanoparticles (e.g., light-absorbing gold nanorods or nanoshells) insidethe treatment fluid, which may increase the efficiency of photo-inducedcavitation in the fluid. The treatment fluid can include excitablefunctional groups (e.g., hydroxyl functional groups) that may besusceptible to excitation by the electromagnetic radiation and which mayincrease the efficiency of pressure wave generation (e.g., due toincreased absorption of radiation). During some treatments, radiationhaving a first wavelength can be used (e.g., a wavelength stronglyabsorbed by the liquid, for instance water) followed by radiation havinga second wavelength not equal to the first wavelength (e.g., awavelength less strongly absorbed by water) but strongly absorbed byanother element, e.g. dentin, dyes, or nanoparticles added to solution.For example, in some such treatments, the first wavelength may helpcreate bubbles in the fluid, and the second wavelength may help disruptthe tissue.

The electromagnetic energy can be applied to the chamber 6 for atreatment time that can be in a range from about one to a few seconds upto about one minute or longer. A treatment procedure can include one toten (or more) cycles of applying electromagnetic energy to the tooth. Afluid can circulate or otherwise move in the chamber during thetreatment process, which advantageously may inhibit heating of the tooth10 (which may cause discomfort to the patient). The movement orcirculation of treatment fluid (e.g., water with a tissue dissolvingagent) in the chamber 6 can bring fresh treatment fluid to tissue andorganic matter as well as flush out dissolved material from thetreatment site. In some treatments using electromagnetic radiation,movement of the treatment fluid (for example small- or large scalerotational flows or turbulent flow) can increase the effectiveness ofthe cleaning (as compared to a treatment with little or no fluidcirculation).

In some implementations, electromagnetic energy can be added to otherfluid motion generation modalities. For example, electromagnetic energycan be delivered to a chamber in which another pressure wave generator(e.g., a liquid jet) is used to generate the acoustic waves.

iv. Acoustic Energy

Acoustic energy (e.g., ultrasonic, sonic, audible, and/or lowerfrequencies) can be generated from electric energy transferred to, e.g.,an ultrasound or other transducer or an ultrasonic tip (or file orneedle) that creates acoustic waves in the treatment fluid. Theultrasonic or other type of acoustic transducer can comprise apiezoelectric crystal that physically oscillates in response to anelectrical signal or a magnetostrictive element that convertselectromagnetic energy into mechanical energy. The transducer can bedisposed in the treatment fluid, for example, in the fluid inside thechamber. As explained herein, ultrasonic or other acoustic devices usedwith the embodiments disclosed herein are preferably broadband and/ormulti-frequency devices.

v. Further Properties of Some Pressure Wave Generators

A pressure wave generator 5 can be placed at a desired location withrespect to the tooth 10. The pressure wave generator 5 creates pressurewaves within the fluid 22 inside the chamber 6 and/or tooth 10 (thegeneration of acoustic waves may or may not create or cause cavitation).The acoustic or pressure waves 23 propagate throughout the fluid 22inside the chamber 6 of the tooth coupler 3 and/or in a tooth chamber ofthe tooth 10, with the fluid 22 in the chamber 6 or tooth 10 serving asa propagation medium for the pressure waves 23. The pressure waves 23can also propagate through tooth material (e.g., dentin). It isbelieved, although not required, that as a result of application of asufficiently high-intensity acoustic wave, acoustic cavitation mayoccur. The collapse of cavitation bubbles may induce, cause, or beinvolved in a number of processes described herein such as, e.g.,sonochemistry, tissue dissociation, tissue delamination, sonoporation,and/or removal of calcified structures. In some embodiments, thepressure wave generator can be configured such that the acoustic waves(and/or cavitation) do not substantially break down natural dentin inthe tooth 110. The acoustic wave field by itself or in addition tocavitation may be involved in one or more of the abovementionedprocesses.

In some implementations, the pressure wave generator 5 generates primarycavitation, which creates acoustic waves, which may in turn lead tosecondary cavitation. The secondary cavitation may be weaker than theprimary cavitation and may be non-inertial cavitation. In otherimplementations, the pressure wave generator 5 generates acoustic wavesdirectly, which may lead to secondary cavitation.

Additional details of pressure wave generators (e.g., which may comprisea pressure wave generator) that may be suitable for use with theembodiments disclosed herein may be found, e.g., in ¶¶ [0191]-[0217],and various other portions of U.S. Patent Publication No. US2012/0237893, published Sep. 20, 2012, which is incorporated byreference herein for all purposes.

c. Enhancement of Cleaning Using Large-Scale Fluid Motion

In some arrangements, bulk fluid motion 24 (e.g., fluid rotation,convection, planar flow, chaotic flow, etc.) can enhance the cleaning ofunhealthy material from a diseased tooth. For example, the fluid motion24 generated in the chamber 6 and/or tooth 10 can impart relativelylarge momentum to the tooth, which can help dissociate and irrigateunhealthy materials from the tooth. Furthermore, the fluid motion 24 caninduce vortices and/or swirl in the tooth 10 that can result in negativepressures (or low positive pressures) near the apical opening 15 of thetooth 10. The resulting negative pressures at the apical opening 15 canprevent or reduce an amount of material extruded through the apicalopening 15 and into the jaw of the patient. By preventing or reducingthe amount of extruded material, the risk of pain and discomfort as wellas infection can be lowered or eliminated, and patient outcomes andcomfort can be substantially improved.

In addition, due to relatively short time scales of the chemicalreaction processes between the fluid 22 and the unhealthy materials ascompared to that of diffusion mechanisms, a faster mechanism of reactantdelivery such as “macroscopic” liquid circulation may be advantageous insome of the embodiments disclosed herein. For example, liquidcirculation with a time scale comparable to (and preferably faster than)that of chemical reaction may help replenish the reactants at thechemical reaction front and/or may help to remove the reactionbyproducts from the reaction site. The relatively large convective timescale, which may relate to effectiveness of the convection process, canbe adjusted and/or optimized depending on, e.g., the location andcharacteristics of the source of circulation. Furthermore, it should beappreciated that the introduction of liquid circulation or other fluidmotion 24 generally does not eliminate the diffusion process, which maystill remain effective within a thin microscopic layer at the chemicalreaction front. Liquid circulation can also cause a strong irrigationeffect at the treatment site (e.g. removing diseased tissue deep in thecanal 13 and/or tubules and small spaces and cracks of the tooth 10) andmay therefore result in loosening and/or removing large and small piecesof debris from the treatment site.

In some arrangements, various properties can be adjusted to enhance bulkfluid motion and/or fluid circulation, e.g., fluid motion in the chamber6 of the tooth coupler 3. For example, the position of the pressure wavegenerator 5 relative to the location of the treatment site can beadjusted. Furthermore, in some embodiments, the pressure wave generator5 can be disposed adjacent the access opening 18 formed in the toothand/or adjacent an access port of the tooth coupler 3. The geometry ofthe space surrounding the pressure wave generator 5 and treatment site(e.g., the geometry of the tooth coupler 3) can also be varied. Itshould also be appreciated that circulation may be affected by theviscosity of the fluid 22 and/or the mechanism of action of the pressurewave generator 5. For example, the pressure wave generator 5, such as ajet of liquid ejected through an inlet opening, a stirrer such as apropeller or a vibrating object, etc., can be selected to enhance fluidmotion of the treatment fluid. In some aspects, the input power of thesource of liquid circulation can also be adjusted, such as the source ofa pump that drives a liquid jet in some embodiments.

2. Enhancement of Other Dental and Endodontic Procedures

In some embodiments, the pressure wave generators 5 disclosed herein canenhance other dental and endodontic procedures. For example, aftercleaning a tooth (e.g., a root canal inside the tooth, a carious regionon or near an exterior surface of the tooth, etc.), the treatment regioncan be filled with an obturation or filler material. The clinician canalso restore damaged or diseased tooth material by building up the toothusing a suitable restoration material. In some embodiments, a fillermaterial can be supplied to the treatment region as a flowable materialand can be hardened to fill the treatment region (e.g., the cleaned rootcanal or carious region, etc.). In some embodiments, a pressure wavegenerator 5 can be activated to supply the obturation materialthroughout the treatment region.

For example, after a root canal procedure, the pressure wave generatorcan supply the flowable obturation material into the tooth and rootcanal. The large-scale fluid movement generated by the pressure wavegenerator 5 can assist in propagating the obturation material throughoutrelatively large spaces, such as the main root canal or canals. Forexample, the pressure wave generator 5 may introduce sufficient momentumsuch that the flowable obturation material propagates throughout thecanal space without introducing additional instrumentation into thetooth. For example, the bulk fluid motion of the obturation materialinto the canal may be such that the clinician may not need to or desireto enlarge the canals. By reducing or eliminating canal enlargement,patient outcomes and pain levels can be improved. In some arrangements,the bulk fluid motion of the flowable obturation material can begenerated at relatively low frequencies produced by the pressure wavegenerator.

In addition to generating large-scale or bulk fluid motion of theobturation material throughout the canal, the pressure wave generators 5disclosed herein can generate higher frequency perturbations topropagate the obturation material into smaller cracks, spaces, andcrevices in the tooth. For example, higher-frequency effects, such asacoustic cavitation, can assist in propagating the filler materialthroughout the tooth.

Accordingly, the pressure wave generators disclosed herein can enhancethe filling and/or restoration of a treatment region such as a rootcanal, carious region of the tooth, etc. For example, the obturationmaterial can be propagated at a distance such that it flows into thetreatment region from a remote pressure wave generator 5 (which may bedisposed outside the tooth). Large-scale or bulk fluid motion of theobturation material can fill larger canal spaces or other treatmentregions without further enlargening the treatment region. Smaller-scaleand/or higher frequency agitation by the pressure wave generator 5 canpropagate the obturation material into smaller cracks and spaces of thetooth. By filling substantially all the cleaned spaces of the tooth, thedisclosed methods can improve patient outcomes relative to other methodsby reducing the risk of infection in spaces unfilled by the obturationmaterial.

3. Enhancement of Treatment Procedures with Broadband Pressure Waves

In various embodiments, disclosed herein, it can be advantageous toconfigure the pressure wave generator 5 to create pressure waves 23having a broadband spectrum, e.g., including numerous or multiplefrequencies of waves. For example, the generation of broadband pressurewaves having multiple frequencies can assist in cleaning a treatmentregion of the tooth and/or in obturation or filling the treatmentregion. FIGS. 2A and 2B are graphs that schematically illustratepossible examples of power that can be generated by differentembodiments of the pressure wave generator 5. These graphs schematicallyshow acoustic power (in arbitrary units) on the vertical axis as afunction of acoustic frequency (in kHz) on the horizontal axis. Theacoustic power in the tooth may influence, cause, or increase thestrength of effects including, e.g., acoustic cavitation (e.g.,cavitation bubble formation and collapse, normal and shear stressformation, as well as microscale flow and microjet formation), acousticstreaming, microerosion, fluid agitation, turbulence, fluid circulationand/or rotational motion, sonoporation, sonochemistry, and so forth,which may act to dissociate organic material in or on the tooth andeffectively clean the undesirable materials, e.g., undesirable organicand/or inorganic materials and deposits. In some embodiments, theseeffects can enhance or enable the obturation or filling of treated rootcanals or other treatment regions of the tooth. For example, theembodiments disclosed herein can advantageously obturate or fillsubstantially the entire canal(s) and/or branch structures therefrom, asexplained in greater detail above. In various embodiments, the pressurewave generator can produce a pressure wave including acoustic power (atleast) at frequencies above: about 1 Hz, about 0.5 kHz, about 1 kHz,about 10 kHz, about 20 kHz, about 50 kHz, about 100 kHz, or greater. Thepressure wave can have acoustic power at other frequencies as well(e.g., at frequencies below the aforelisted frequencies).

The graph in FIG. 2A represents a schematic example of acoustic powergenerated by a liquid jet impacting a surface disposed within a chamberon or around the tooth that is substantially filled with liquid and bythe interaction of the liquid jet with fluid in the chamber. Thisschematic example shows a broadband spectrum 190 of acoustic power withsignificant power extending from about 1 Hz to about 1000 kHz,including, e.g., significant power in a range of about 1 kHz to about1000 kHz (e.g., the bandwidth can be about 1000 kHz). The bandwidth ofthe acoustic energy spectrum may, in some cases, be measured in terms ofthe 3-decibel (3-dB) bandwidth (e.g., the full-width at half-maximum orFWHM of the acoustic power spectrum). In various examples, a broadbandacoustic power spectrum can include significant power in a bandwidth ina range from about 1 Hz to about 500 kHz, in a range from about 1 kHz toabout 500 kHz, in a range from about 10 kHz to about 100 kHz, or someother range of frequencies. In some implementations, a broadbandspectrum can include acoustic power above about 1 MHz. In someembodiments, the pressure wave generator can produce broadband acousticpower with peak power at about 10 kHz and a bandwidth of about 100 kHz.In various embodiments, the bandwidth of a broadband acoustic powerspectrum is greater than about 10 kHz, greater than about 50 kHz,greater than about 100 kHz, greater than about 250 kHz, greater thanabout 500 kHz, greater than about 1 MHz, or some other value. In somecleaning methods, acoustic power between about 1 Hz and about 200 kHz,e.g., in a range of about 20 kHz to about 200 kHz may be particularlyeffective at cleaning teeth. The acoustic power can have substantialpower at frequencies greater than about 1 kHz, greater than about 10kHz, greater than about 100 kHz, or greater than about 500 kHz.Substantial power can include, for example, an amount of power that isgreater than 10%, greater than 25%, greater than 35%, or greater than50% of the total acoustic power (e.g., the acoustic power integratedover all frequencies). In some arrangements, the broadband spectrum 190can include one or more peaks, e.g., peaks in the audible, ultrasonic,and/or megasonic frequency ranges.

The graph in FIG. 2B represents a schematic example of acoustic powergenerated by an ultrasonic transducer disposed in a chamber on or aroundthe tooth that is substantially filled with liquid. This schematicexample shows a relatively narrowband spectrum 192 of acoustic powerwith a highest peak 192 a near the fundamental frequency of about 30 kHzand also shows peaks 192 b near the first few harmonic frequencies. Thebandwidth of the acoustic power near the peak may be about 5 to 10 kHz,and can be seen to be much narrower than the bandwidth of the acousticpower schematically illustrated in FIG. 2A. In other embodiments, thebandwidth of the acoustic power can be about 1 kHz, about 5 kHz, about10 kHz, about 20 kHz, about 50 kHz, about 100 kHz, or some other value.The acoustic power of the example spectrum 192 has most of its power atthe fundamental frequency and first few harmonics, and therefore theultrasonic transducer of this example may provide acoustic power at arelatively narrow range of frequencies (e.g., near the fundamental andharmonic frequencies). The acoustic power of the example spectrum 190exhibits relatively broadband power (with a relatively high bandwidthcompared to the spectrum 192), and the example liquid jet can provideacoustic power at significantly more frequencies than the exampleultrasonic transducer. For example, the relatively broadband power ofthe example spectrum 190 illustrates that the example jet deviceprovides acoustic power at these multiple frequencies with energysufficient to break the bonds between the decayed and healthy materialso as to substantially remove the decayed material from the cariousregion.

It is believed, although not required, that pressure waves havingbroadband acoustic power (see, e.g., the example shown in FIG. 2A) cangenerate acoustic cavitation or other means of cleaning and disinfectionthat is more effective at cleaning teeth (including cleaning, e.g.,unhealthy materials in or on the tooth) than cavitation generated bypressure waves having a narrowband acoustic power spectrum (see, e.g.,the example shown in FIG. 2B). One reason is that in a broadbandspectrum the energy is delivered as substantially all length scalescovered in the range and therefore targeting substantially allstructures whose dimensions fall within that range of length scales.Further, broadband acoustic power can also generate sufficient energy atfrequencies capable of obturating or filling a root canal or othertreatment region (such as a treated carious region on an exteriorsurface of the tooth). For example, a broadband spectrum of acousticpower can produce a relatively broad range of bubble sizes in thecavitation cloud and on the surfaces on the tooth, and the implosion ofthese bubbles may be more effective at disrupting tissue than bubbleshaving a narrow size range. Relatively broadband acoustic power may alsoallow acoustic energy to work on a range of length scales, e.g., fromthe cellular scale up to the tissue scale. Accordingly, pressure wavegenerators that produce a broadband acoustic power spectrum (e.g., someembodiments of a liquid jet) can be more effective at tooth cleaning forsome treatments than pressure wave generators that produce a narrowbandacoustic power spectrum. In some embodiments, multiple narrowbandpressure wave generators can be used to produce a relatively broad rangeof acoustic power. For example, multiple ultrasonic tips, each tuned toproduce acoustic power at a different peak frequency, can be used. Asused herein, broadband frequencies and broadband frequency spectrum isdefined regardless of secondary effects such as harmonics of the mainfrequencies and regardless of any noise introduced by measurement ordata processing (e.g., FFT); that is, these terms should be understoodwhen only considering all main frequencies activated by the pressurewave generator.

FIG. 2C is a graph of an acoustic power spectrum 1445 generated atmultiple frequencies by the pressure wave generators disclosed herein.For example, the spectrum 1445 in FIG. 2C is an example of acousticpower generated by a liquid jet impacting a surface disposed within achamber on, in, or around the tooth that is substantially filled withliquid and by the interaction of the liquid jet with fluid in thechamber. The spectrum 1445 of FIG. 2C represents acoustic power detectedby a sensor spaced apart from the source of the acoustic energy, e.g.,the pressure wave generator. The data was acquired inside an insulatedwater tank when the distance between the power wave generator and thehydrophone (e.g., sensor) being about 8 inches. The vertical axis of theplot represents a measure of acoustic power: Log (P_(acoustic) ²),referred to herein as “power units”. The units of P_(acoustic) in themeasurement were μPa (micro Pascal). Thus, it should be appreciated thatthe actual power at the source may be of a different magnitude becausethe sensor is spaced from the acoustic power generator. However, thegeneral profile of the power spectrum at the source should be the sameas the spectrum 1445 detected at the sensor and plotted in FIG. 2C. Itshould also be understood that, although the plot shows frequencies onlyup to 100 KHz, the power above 100 KHz was greater than zero (althoughnot plotted in the figures shown herein). It should further be notedthat, as would be appreciated by one skilled in the art, the plot andthe values would also depend on other parameters, such as, for example,the size and shape of the tank in which data was acquired, theinsulation of the inner surface of the tank, the relative distancebetween the source (e.g., power wave generator), and the free watersurface of the tank.

As shown in FIG. 2C, the spectrum 1445 can include acoustic power atmultiple frequencies 1447, e.g., multiple discrete frequencies. Inparticular, the spectrum 1445 illustrated in FIG. 2C includes acousticpower at frequencies in a range of about 1 Hz to about 100 KHz. Theacoustic power can be in a range of about 10 power units to about 80power units at these frequencies. In some arrangements, the acousticpower can be in a range of about 30 power units to about 75 power unitsat frequencies in a range of about 1 Hz to about 10 kHz. In somearrangements, the acoustic power can be in a range of about 10 powerunits to about 30 power units at frequencies in a range of about 1 KHzto about 100 kHz. In some embodiments, for example, the broadbandfrequency range of the pressure waves generated by the pressure wavegenerators disclosed herein can comprise a substantially white noisedistribution of frequencies.

Pressure wave generators that generate acoustic power associated withthe spectrum 1445 of FIG. 2C can advantageously and surprisingly cleanundesirable materials from teeth. As explained above, the generation ofpower at multiple frequencies can help to remove various types oforganic and/or inorganic materials that have different material orphysical characteristics, and/or different bonding strengths at variousfrequencies. For example, some undesirable materials may be removed fromthe teeth and/or gums at relatively low acoustic frequencies, whileother materials may be removed from the teeth at relatively highacoustic frequencies, while still other materials may be removed atintermediate frequencies between the relatively low and relatively highfrequencies. As shown in FIG. 2C, lower frequency cleaning phases can beactivated at higher powers, and higher frequency cleaning phases can beactivated at lower powers. In other embodiments, low frequency cleaningphases may be activated at relatively low powers, and high frequencycleaning phases may be activated at relatively high powers. Pressurewave generators that generate acoustic power at multiple frequencies(e.g., multiple discrete frequencies) are capable of cleaningundesirable materials and decayed matter from interior and/or exteriorportions of teeth.

In the embodiments disclosed herein, treatment procedures can beactivated to generate acoustic power at various frequency ranges forcleaning procedures and/or for obturation procedures. For example, sometreatment phases may be activated at lower frequencies, and othertreatment phases may be activated at higher frequencies. The pressurewave generators disclosed herein can be adapted to controllably generateacoustic power at any suitable frequencies 1447 of the spectrum 1445.For example, the pressure wave generators disclosed herein can beadapted to generate power at multiple frequencies 1447 simultaneously,e.g., such that the delivered acoustic power in a particular treatmentprocedure can include a desired combination of individual frequencies.For example, in some procedures, power may be generated across theentire frequency spectrum 1445. In some treatment phases, the pressurewave generator can deliver acoustic power at only relatively lowfrequencies, and in other treatment phases, the pressure wave generatorcan deliver power at only relatively high frequencies, as explainedherein. Further, depending on the desired treatment procedure, thepressure wave generator can automatically or manually transition betweenfrequencies 1447 according to a desired pattern, or can transitionbetween frequencies 1447 randomly. In some arrangements, relatively lowfrequencies can be associated with large-scale bulk fluid movement, andrelatively high frequencies can be associated with small-scale,high-energy oscillations.

In some embodiments, the treatment procedure may include one or moretreatment phases. In each treatment phase, energy can be applied at adifferent frequency or band of frequencies. For example, in one phase,energy (e.g., pressure or acoustic waves) propagating at a relativelylow frequency (or band of frequencies) may be generated. The lowfrequency pressure waves can interact with the treatment fluid in thechamber and can induce removal of large-scale dental deposits ormaterials. Without being limited by theory, for cleaning procedures, thelow frequency pressure waves can remove a substantial portion of theunhealthy materials in the tooth. For example, the low frequency wavesmay have a sufficiently high energy at suitably low frequencies toremove large deposits or materials from the tooth. The acoustic power atthe relatively low frequencies can include acoustic power at anysuitable low-frequency band of the power spectrum of the pressure wavegenerator (see, e.g., FIG. 2A). For example, in some embodiments, theacoustic power in the first, low-frequency range can include one or morefrequencies in a range of about 0.1 Hz to about 100 Hz, for example in arange of about 1 Hz to about 50 Hz in some arrangements. For obturationprocedures, low frequency waves may be suitable for conveying obturationmaterial through large spaces and canals of the tooth.

In another phase, acoustic energy may be generated at relatively highfrequencies. At higher frequencies, the pressure wave generator can beconfigured to remove smaller deposits and debris in cleaning procedures.For example, at higher frequencies, the pressure waves can propagatethrough the treatment fluid. The higher frequency waves can removesmaller portions from relatively small locations, such as crevices,cracks, spaces, and irregular surfaces of the tooth. In someembodiments, degassed liquid can be used to enhance the removal ofmatter from these small spaces. When the higher frequency cleaning isperformed after the lower frequency cleaning, in some embodiments, thehigh frequency waves (and/or intermediate frequency waves) can clean theremainder of the unhealthy material left behind from the low frequencycleaning. In the relatively high frequency phases, acoustic energy canbe generated in a range of about 10 kHz to about 1000 kHz, e.g., in arange of about 100 kHz to about 500 kHz. For obturation procedures,higher frequency pressure waves may assist in filling small spaces ofthe tooth and canals.

In some embodiments, the treatment procedure can progress from therelatively low frequencies (or bands of frequencies) toward higherfrequencies (or bands of frequencies). For example, the procedure canmove from the relatively low frequency phase(s), through intermediatefrequency phase(s), until the high frequency phase(s) are reached. Thus,in some embodiments, the treatment procedure can provide a gradualand/or substantially continuous transition between relatively low andrelatively high frequencies. As the treatment progresses through thefrequencies, unhealthy dental deposits or materials of varying size andtype can be removed by the pressure wave generator. In otherembodiments, however, the treatment procedure can transition or switchbetween frequencies (or bands of frequencies) or phases (e.g., betweenhigh, low and/or intermediate frequencies or bands of frequencies) atdiscrete levels. At various intermediate frequency ranges, acousticenergy can be generated in a range of about 100 Hz to about 10 kHz. Forexample, in some embodiments, the various phases of the treatmentprocedures described above may be activated by the user or clinician, orthe pressure wave generator can be configured to automaticallytransition between the phases. In some embodiments, for example, thepressure wave generator can randomly switch between high, low, andintermediate frequencies.

Various treatment procedures may include any suitable number oftreatment phases at various different frequencies. Furthermore, althoughvarious low- and high-frequency phases may be described above asoccurring in a particular order, in other embodiments, the order ofactivating the low- and high-frequency phases, and/or any intermediatefrequency phases, may be any suitable order. Furthermore, the treatmentprocedures and phases described herein can also be used to fill orobturate treatment regions of a tooth after cleaning. In obturationprocedures, the embodiments disclosed herein can advantageously obturateor fill substantially the entire canal(s) and/or branch structurestherefrom, as explained in greater detail herein.

4. Enhancing Treatment Procedures with Degassed Fluids

As described herein, the treatment fluid (and/or any of solutions addedto the treatment fluid) can be degassed compared to normal liquids usedin dental offices. For example, degassed distilled water can be usedwith or without the addition of chemical agents or solutes. Forobturation and/or restoration procedures, the obturation or fillingmaterial (and components thereof) may be substantially degassed.Degassed obturation or filling materials can prevent bubbles from beingor forming in the filling material, which can assist in filling smallspaces of the canal system.

a. Examples of Possible Effects of Dissolved Gases in the TreatmentFluid

In some procedures, the treatment fluid can include dissolved gases(e.g., air). For example, the fluids used in dental offices generallyhave a normal dissolved gas content (e.g., determined from thetemperature and pressure of the fluid based on Henry's law). Duringcleaning procedures using a pressure wave generator, the acoustic fieldof the pressure wave generator and/or the flow or circulation of fluidsin the chamber can cause some of the dissolved gas to come out ofsolution and form bubbles.

The bubbles can block small passageways or cracks or surfaceirregularities in the tooth, and such blockages can act as if there werea “vapor lock” in the small passageways. In some such procedures, thepresence of bubbles may at least partially block, impede, or redirectpropagation of acoustic waves past the bubbles and may at leastpartially inhibit or prevent cleaning action from reaching, for example,unhealthy dental materials in tubules and small spaces of the tooth 10.The bubbles may block fluid flow or circulation from reaching thesedifficult-to-reach, or otherwise small, regions, which may prevent orinhibit a treatment solution from reaching these areas of the tooth.

In certain procedures, cavitation is believed to play a role in cleaningthe tooth. Without wishing to be bound by any particular theory, thephysical process of cavitation inception may be, in some ways, similarto boiling. One possible difference between cavitation and boiling isthe thermodynamic paths that precede the formation of the vapor in thefluid. Boiling can occur when the local vapor pressure of the liquidrises above the local ambient pressure in the liquid, and sufficientenergy is present to cause the phase change from liquid to a gas. It isbelieved that cavitation inception can occur when the local ambientpressure in the liquid decreases sufficiently below the saturated vaporpressure, which has a value given in part by the tensile strength of theliquid at the local temperature. Therefore, it is believed, although notrequired, that cavitation inception is not determined by the vaporpressure, but instead by the pressure of the largest nuclei, or by thedifference between the vapor pressure and the pressure of the largestnuclei. As such, it is believed that subjecting a fluid to a pressureslightly lower than the vapor pressure generally does not causecavitation inception. However, the solubility of a gas in a liquid isproportional to pressure; therefore lowering the pressure may tend tocause some of the dissolved gas inside the fluid to be released in theform of gas bubbles that are relatively large compared to the size ofbubbles formed at cavitation inception. These relatively large gasbubbles may be misinterpreted as being vapor cavitation bubbles, andtheir presence in a fluid may have been mistakenly described in certainreports in the literature as being caused by cavitation, when cavitationmay not have been present.

In the last stage of collapse of vapor cavitation bubbles, the velocityof the bubble wall may even exceed the speed of sound and create strongshock waves inside the fluid. The vapor cavitation bubble may alsocontain some amount of gas, which may act as a buffer and slow down therate of collapse and reduce the intensity of the shockwaves. Therefore,in certain procedures that utilize cavitation bubbles for toothcleaning, it may be advantageous to reduce the amount of the dissolvedair in the fluid to prevent such losses.

The presence of bubbles that have come out of solution from thetreatment fluid may lead to other disadvantages during certainprocedures. For example, if the pressure wave generator producescavitation, the agitation (e.g. pressure drop) used to induce thecavitation may cause the release of the dissolved air content before thewater molecules have a chance to form a cavitation bubble. Thealready-formed gas bubble may act as a nucleation site for the watermolecules during the phase change (which was intended to form acavitation bubble). When the agitation is over, the cavitation bubble isexpected to collapse and create pressure waves. However, cavitationbubble collapse might happen with reduced efficiency, because thegas-filled bubble may not collapse and may instead remain as a bubble.Thus, the presence of gas in the treatment fluid may reduce theeffectiveness of the cavitation process as many of the cavitationbubbles may be wasted by merging with gas-filled bubbles. Additionally,bubbles in the fluid may act as a cushion to damp pressure wavespropagating in the region of the fluid comprising the bubbles, which maydisrupt effective propagation of the pressure waves past the bubbles.Some bubbles may either form on or between tooth surfaces, or betransferred there by the flow or circulation of fluid in the tooth. Thebubbles may be hard to remove due to relatively high surface tensionforces. This may result in blocking the transfer of chemicals and/orpressure waves into the irregular surfaces and small spaces in andbetween teeth, and therefore may disrupt or reduce the efficacy of thetreatment. Existence of a very small amount of gas inside the fluid mayhowever be beneficial as the gas may form very small volume bubbleswhich then act as the nucleation site for vapor cavitation to occur (andtherefore facilitate vapor cavitation), and due to their small volumecompared to the volume of the actual vapor cavitation, their damping andinterrupting effects may be negligible.

b. Examples of Degassed Treatment Fluids

Accordingly, it may be advantageous in some systems and methods to use adegassed fluid, which can inhibit, reduce, or prevent bubbles fromcoming out of solution during treatments as compared to systems andmethods that use normal (e.g., non-degassed) fluids. In dentalprocedures in which the treatment fluid has a reduced gas content(compared with the normal fluids) tooth surfaces or tiny spaces in thetooth may be free of bubbles that have come out of solution. Acousticwaves generated by the pressure wave generator can propagate through thedegassed fluid to reach and clean the surfaces, cracks, and tooth spacesand cavities. In some procedures, the degassed fluid can be able topenetrate spaces as small as about 500 microns, 200 microns, 100microns, 10 microns, 5 microns, 1 micron, or smaller, because thedegassed fluid is sufficiently gas-free that bubbles are inhibited fromcoming out of solution and blocking these spaces (as compared to use offluids with normal dissolved gas content).

For example, in some systems and methods, the degassed fluid can have adissolved gas content that is reduced when compared to the “normal” gascontent of water. For example, according to Henry's law, the “normal”amount of dissolved air in water (at 25 C and 1 atmosphere) is about 23mg/L, which includes about 9 mg/L of dissolved oxygen and about 14 mg/Lof dissolved nitrogen. In some embodiments, the degassed fluid has adissolved gas content that is reduced to approximately 10%-40% of its“normal” amount as delivered from a source of fluid (e.g., beforedegassing). In other embodiments, the dissolved gas content of thedegassed fluid can be reduced to approximately 5%-50% or 1%-70% of thenormal gas content of the fluid. In some treatments, the dissolved gascontent can be less than about 70%, less than about 50%, less than about40%, less than about 30%, less than about 20%, less than about 10%, lessthan about 5%, or less than about 1% of the normal gas amount.

In some embodiments, the amount of dissolved gas in the degassed fluidcan be measured in terms of the amount of dissolved oxygen (rather thanthe amount of dissolved air), because the amount of dissolved oxygen canbe more readily measured (e.g., via titration or optical orelectrochemical sensors) than the amount of dissolved air in the fluid.Thus, a measurement of dissolved oxygen in the fluid can serve as aproxy for the amount of dissolved air in the fluid. In some suchembodiments, the amount of dissolved oxygen in the degassed fluid can bein a range from about 1 mg/L to about 3 mg/L, in a range from about 0.5mg/L to about 7 mg/L, or some other range. The amount of dissolvedoxygen in the degassed fluid can be less than about 7 mg/L, less thanabout 6 mg/L, less than about 5 mg/L, less than about 4 mg/L, less thanabout 3 mg/L, less than about 2 mg/L, or less than about 1 mg/L.

In some embodiments, the amount of dissolved gas in the degassed fluidcan be in a range from about 2 mg/L to about 20 mg/L, in a range fromabout 1 mg/L to about 12 mg/L, or some other range. The amount ofdissolved gas in the degassed fluid can be less than about 20 mg/L, lessthan about 18 mg/L, less than about 15 mg/L, less than about 12 mg/L,less than about 10 mg/L, less than about 8 mg/L, less than about 6 mg/L,less than about 4 mg/L, or less than about 2 mg/L.

In other embodiments, the amount of dissolved gas can be measured interms of air or oxygen percentage per unit volume. For example, theamount of dissolved oxygen (or dissolved air) can be less than about 5%by volume, less than about 1% by volume, less than about 0.5% by volume,or less than about 0.1% by volume.

The amount of dissolved gas in a liquid can be measured in terms of aphysical property such as, e.g., fluid viscosity or surface tension. Forexample, degassing water tends to increase its surface tension. Thesurface tension of non-degassed water is about 72 mN/m at 20° C. In someembodiments, the surface tension of degassed water can be about 1%, 5%,or 10% greater than non-degassed water.

In some treatment methods, one or more secondary fluids can be added toa primary degassed fluid (e.g., an antiseptic solution can be added todegassed distilled water). In some such methods, the secondarysolution(s) can be degassed before being added to the primary degassedfluid. In other applications, the primary degassed fluid can besufficiently degassed such that inclusion of the secondary fluids (whichcan have normal dissolved gas content) does not increase the gas contentof the combined fluids above what is desired for a particular dentaltreatment.

In various implementations, the treatment fluid can be provided asdegassed liquid inside sealed bags or containers. The fluid can bedegassed in a separate setup in the operatory before being added to afluid reservoir. In an example of an “in-line” implementation, the fluidcan be degassed as it flows through the system, for example, by passingthe fluid through a degassing unit attached along a fluid line (e.g.,the fluid inlet). Examples of degassing units that can be used invarious embodiments include: a Liqui-Cel® MiniModule® Membrane Contactor(e.g., models 1.7×5.5 or 1.7×8.75) available from Membrana—Charlotte(Charlotte, N.C.); a PermSelect® silicone membrane module (e.g., modelPDMSXA-2500) available from MedArray, Inc. (Ann Arbor, Mich.); and aFiberFlo® hollow fiber cartridge filter (0.03 micron absolute) availablefrom Mar Cor Purification (Skippack, Pa.). The degassing can be doneusing any of the following degassing techniques or combinations ofthereof: heating, helium sparging, vacuum degassing, filtering,freeze-pump-thawing, and sonication.

In some embodiments, degassing the fluid can include de-bubbling thefluid to remove any small gas bubbles that form or may be present in thefluid. De-bubbling can be provided by filtering the fluid. In someembodiments, the fluid may not be degassed (e.g., removing gas dissolvedat the molecular level), but can be passed through a de-bubbler toremove the small gas bubbles from the fluid.

In some embodiments, a degassing system can include a dissolved gassensor to determine whether the treatment fluid is sufficiently degassedfor a particular treatment. A dissolved gas sensor can be disposeddownstream of a mixing system and used to determine whether mixing ofsolutes has increased the dissolved gas content of the treatment fluidafter addition of solutes, if any. A solute source can include adissolved gas sensor. For example, a dissolved gas sensor can measurethe amount of dissolved oxygen in the fluid as a proxy for the totalamount of dissolved gas in the fluid, since dissolved oxygen can bemeasured more readily than dissolved gas (e.g., nitrogen or helium).Dissolved gas content can be inferred from dissolved oxygen contentbased at least partly on the ratio of oxygen to total gas in air (e.g.,oxygen is about 21% of air by volume). Dissolved gas sensors can includeelectrochemical sensors, optical sensors, or sensors that perform adissolved gas analysis. Examples of dissolved gas sensors that can beused with embodiments of various systems disclosed herein include aPro-Oceanus GTD-Pro or HGTD dissolved gas sensor available fromPro-Oceanus Systems Inc. (Nova Scotia, Canada) and a D-Opto dissolvedoxygen sensor available from Zebra-Tech Ltd. (Nelson, New Zealand). Insome implementations, a sample of the treatment can be obtained andgases in the sample can be extracted using a vacuum unit. The extractedgases can be analyzed using a gas chromatograph to determine dissolvedgas content of the fluid (and composition of the gases in some cases).

Accordingly, fluid delivered to the tooth from a fluid inlet and/or thefluid used to generate the jet in a liquid jet device can comprise adegassed fluid that has a dissolved gas content less than normal fluid.The degassed fluid can be used, for example, to generate thehigh-velocity liquid beam for generating acoustic waves, tosubstantially fill or irrigate a chamber, to provide a propagationmedium for acoustic waves, to inhibit formation of air (or gas) bubblesin the chamber, and/or to provide flow of the degassed fluid into smallspaces in the tooth (e.g., cracks, irregular surfaces, tubules, etc.).In embodiments utilizing a liquid jet, use of a degassed fluid caninhibit bubbles from forming in the jet due to the pressure drop at anozzle orifice where the liquid jet is formed.

Thus, examples of methods for dental and/or endodontic treatmentcomprise flowing a degassed fluid onto a tooth or tooth surface or intoa chamber. The degassed fluid can comprise a tissue dissolving agentand/or a decalcifying agent. The degassed fluid can have a dissolvedoxygen content less than about 9 mg/L, less than about 7 mg/L, less thanabout 5 mg/L, less than about 3 mg/L, less than about 1 mg/L, or someother value. A fluid for treatment can comprise a degassed fluid with adissolved oxygen content less than about 9 mg/L, less than about 7 mg/L,less than about 5 mg/L, less than about 3 mg/L, less than about 1 mg/L,or some other value. The fluid can comprise a tissue dissolving agentand/or a decalcifying agent. For example, the degassed fluid cancomprise an aqueous solution of less than about 6% by volume of a tissuedissolving agent and/or less than about 20% by volume of a decalcifyingagent.

FIG. 3A illustrates images of root canals that compare the use ofnon-degassed liquid and degassed liquid in the disclosed pressure wavegenerators for a cleaning procedure. As shown in image 1201 on the leftside of FIG. 3A, the use of non-degassed liquid may cause bubbles toform in the canals, which may inhibit the propagation of energy in somearrangements. As shown in image 1202 on the right side of FIG. 3A, theuse of degassed liquid may substantially prevent the formation ofbubbles in the root canals when exposed to broadband acoustic orpressure waves. FIG. 3B is a plot comparing the power output fortechniques using non-degassed and degassed liquids. The power outputsplotted in FIG. 3B are measured based on the liquid jet device describedherein. As shown in FIG. 3B, at higher acoustic frequencies, the use ofdegassed liquid in the disclosed systems can generate significantly morepower than in techniques using non-degassed liquid. As illustrated inFIG. 3B, for example, at high acoustic frequencies, the differencebetween power generated by degassed and non-degassed liquids can begiven by ΔP, which can be in a range of about 5 dB to about 25 dB forfrequencies in a range of about 20 kHz to about 200 kHz. For example,for frequencies in a range of about 70 kHz to about 200 kHz, ΔP can bein a range of about 10 dB to about 25 dB. At lower frequencies, thedifferences in power generated by degassed and non-degassed techniquesmay not be noticeable. At lower frequencies, relatively high powers maybe generated even with non-degassed liquid because low frequency,large-scale fluid motion may produce substantial momentum thatcontributes to the cleaning of the tooth.

II. Examples of Handpieces

FIG. 4A is a schematic side view of a tooth coupler comprising ahandpiece 3A having a cleaning mode and an obturation or filling mode.FIG. 4B is a schematic side cross-sectional view of the handpiece 3Ashown in FIG. 4A. The dental handpiece 3A can include a body or housingshaped to be gripped by the clinician. In some embodiments, the pressurewave generator 5 can be coupled to or formed with a distal portion ofthe handpiece 3A. Before a treatment procedure (e.g., a cleaningprocedure, an obturation procedure, a restorative procedure, etc.), theclinician can connect the handpiece 3A to an interface member 4 of thesystem 1. The interface member 4 can be in fluid and/or electricalcommunication with the console 2 (see FIGS. 1A-1D), which can beconfigured to control the treatment procedures. The interface member 4may be similar to or the same as the interface members disclosed in U.S.patent application Ser. No. 14/172,809, filed on Feb. 4, 2014, entitled“DENTAL TREATMENT SYSTEM,” and in U.S. Patent Publication No. US2012/0237893, each of which is incorporated by reference herein in itsentirety and for all purposes. In some embodiments, the handpiece 3A cancomprise a wireless chip (such as a radio frequency identification, orRFID, chip) configured to wirelessly communicate with the console 2 orwith a reader that is in communication with the console 2. The RFID chipcan be used to confirm what type of handpiece 3A is being used with thesystem 1. For example, the RFID chip can store information regarding thehandpiece 3A, such as whether the handpiece 3A is a cleaning handpiece,and obturation handpiece, or both. This information can be used to trackinformation regarding the treatment procedure and/or to ensure that theproper procedure is being performed with the particular handpiece 3A.Additional details of such a wireless chip system for the handpiece aredisclosed in U.S. patent application Ser. No. 14/172,809, filed on Feb.4, 2014, entitled “DENTAL TREATMENT SYSTEM,” which is incorporated byreference herein in its entirety and for all purposes.

The clinician can manipulate the handpiece 3A such that the pressurewave generator 5 is positioned near the treatment region on or in thetooth. The clinician can activate the pressure wave generator 5 usingcontrols on the console 2 and/or the handpiece 3A, and can perform thedesired treatment procedure. After performing the treatment procedure,the clinician can disconnect the handpiece 3A from the interface member4 and can remove the handpiece 3A from the system 1. The handpiece 3Ashown in FIGS. 4A-4B can advantageously be configured to clean a toothwhen the handpiece 3A is in the cleaning mode and to obturate or fillthe tooth when the handpiece is in the obturation mode. In otherembodiments, the handpiece 3A may only be configured to clean the toothor may only be configured to obturate the treatment region. As explainedabove, the clinician can position the handpiece 3A against the treatmentregion during a treatment procedure. The handpiece 3A in FIGS. 4A-4B caninclude a sealing cap 40 at a distal portion 19 of the handpiece 3A. Thesealing cap 40 can be sized and shaped to be positioned against aportion of a tooth to be treated. In some arrangements, the cap 40 canbe held against the treatment tooth by the clinician during theprocedure. In other arrangements, the cap 40 can be attached to thetooth.

In some embodiments, a pressure wave generator 5 can be disposed nearthe distal portion 19 of the handpiece 19. For example, as shown in FIG.4B, the sealing cap 40 can be disposed about the pressure wave generator5. The sealing cap 40 can at least partially define a chamber 6configured to retain fluid during a treatment procedure. The pressurewave generator 5 can be any suitable apparatus configured to generatepressure waves sufficient to clean and/or obturate or fill a tooth, asexplained in more detail herein. In the embodiment of FIGS. 4A-4B, thepressure wave generator 5 comprises a fluid jet device. For example, thepressure wave generator 5 can comprise a guide tube 21 having one ormore openings 42 near a distal portion of the guide tube 21. However, asexplained herein, other types of pressure wave generators may besuitable.

A high pressure supply line 26 and a waste line 44 can pass through thehandpiece 3A and to the console 2 by way of an interface member 4 thatcouples the handpiece 3A to various conduits coupled to the console 2.The high pressure supply line 26 can extend from the console 2 (see FIG.1A) to the handpiece 3A and can be configured to convey pressurizedfluid to the guide tube 21. For example, the high pressure supply line26 can be in fluid communication with a high pressure pump and othercomponents in the console 2. The pump can pressurize the fluid (e.g.,treatment fluid) such that the fluid passes through the handpiece 3Aalong the supply line 26 at relatively high pressures. Additionalexamples of systems including high pressure pumps, fluid supply lines,and other system components that can be used in the embodimentsdisclosed herein may be found in FIGS. 4-5H and the associateddisclosure of U.S. patent application Ser. No. 14/172,809, filed on Feb.4, 2014, entitled “DENTAL TREATMENT SYSTEM,” and in U.S. PatentPublication No. US 2012/0237,893, each of which is incorporated byreference herein in its entirety and for all purposes.

As explained herein, during a cleaning procedure, high pressure cleaningfluids (e.g., water, EDTA, bleach, etc.) may be conveyed through thehigh pressure supply line 26 to the guide tube 21. A nozzle orifice (notshown) at the distal portion 19 of the handpiece 3A can be configured toform a liquid jet that passes along the guide tube 21. During a cleaningprocedure, the liquid jet can pass through treatment fluid contained inthe chamber 6 formed at least in part by the sealing cap 40. Interactionof the jet with the fluid in the chamber 6 (e.g., by way of theopening(s) 42) can generate pressure waves that propagate through thetreatment region to substantially clean the tooth, including smallspaces and cracks in the tooth. An impingement surface 33 can bedisposed at the distal end of the guide tube 21 and can be shaped toprevent the jet from damaging the anatomy. The jet can impact theimpingement surface 33, and the cleaning fluids can pass through theopening(s) 42 and into the treatment region to assist in cleaning thetreatment region.

Similarly, during an obturation procedure, a flowable obturationmaterial can be conveyed along the high pressure supply line 26 and canalso form a jet that passes through the guide tube 21. Interaction ofthe jet with the surrounding fluid (such as flowable obturation materialthat fills the chamber 6) by way of the opening 42 can generate pressurewaves, which may cause the flowable obturation material to fill smallspaces and cracks in the tooth. The flowable obturation material canthus pass through the same opening(s) 42 as the cleaning fluid. When theflowable obturation material hardens or is cured, the obturationmaterial can substantially fill the treatment region to prevent bacteriaor other undesirable materials from reforming in the cleaned treatmentregion. The console 2 may comprise pumps and degassers. For example, theconsole can include high pressure pumps for pressurizing the obturationmaterial and a degassing apparatus for degassing the obturationmaterial. In the embodiment of FIGS. 4A-4B, the obturation or fillingmaterial in the reservoir 27 may be degassed before being disposed inthe handpiece 3A.

One or more suction ports 43 can also be formed near the distal portion19 of the handpiece 3A. The suction port 43 can fluidly communicate withthe waste line 44, which can be driven by a vacuum pump (or othersuitable suction system). Waste fluids can be drawn into the waste line44 by way of the suction port 43. The waste fluids can be passed to asuitable waste collection system for disposal.

The handpiece 3A can include a switch 25 configured to change betweentreatment modes. The switch 25 can comprise a rotatable member thatswitches between a cleaning branch lumen 28 and an obturation or fillingmaterial reservoir 27. In some arrangements, the rotatable member of theswitch 25 can comprise a tubular member through which suitable flowablematerials can pass. For example, the switch 25 can be moved to acleaning mode 25A, in which cleaning fluids can pass through thecleaning branch 28 of the high pressure supply line 26 to the guide tube21 at the distal portion 19 of the handpiece 3A. The clinician may alsointeract with the console 2 to activate the cleaning procedure. When theswitch 25 is in the cleaning mode 25A, the pressurized cleaning fluids(e.g., water, EDTA, bleach, etc.) may pass through the interface member4, through the switch 25, and into the cleaning branch lumen 28. Thecleaning branch lumen 28 can rejoin the primary supply line 26 distalthe switch 25, and the cleaning fluid can be conveyed to the guide tube21. When the cleaning fluids interact with surrounding fluid in thechamber 6, pressure waves can propagate through the treatment region.The generated pressure waves can cause the cleaning fluids to passthrough tiny spaces and cracks of the treatment region to substantiallyclean the tooth.

In the embodiments disclosed herein, the reservoir 27 may comprise wallsthat have weakened portions that communicate with the supply line 26.When fluid (e.g., the obturation or filling material) is driven with asufficiently high pressure, the fluid can break through the weakenedportions of the wall to create an opening between the supply line 26 andthe reservoir 27. The pressurized fluid can flow through the opening insome arrangements. Still other connections between the reservoirs andfluid supply lines may be suitable, including, e.g., valves, etc. Thevolume of the reservoir 27 may be sufficiently large so as to retainsufficient filing material for the filling procedure. For example, insome embodiments, the volume of the reservoir should be sized to hold avolume at least as large as the volume of the treatment region (e.g.,the volume of the tooth interior for root canal treatments) plus thevolume of the supply line 26 between the reservoir 27 and the treatmentregion. The additional volume of material may be useful in ensuring thatthe pressure wave generator 5 is supplied with sufficient materials soas to be able to generate sufficient pressure waves to fill thetreatment region.

When the cleaning treatment is complete, the clinician can move theswitch from the cleaning mode 25A to an obturation or filling mode 25B.The clinician can interact with the console 2 to activate an obturationprocedure in some embodiments. The obturation reservoir 27 can be atleast partially filled with an obturation or filler material. In someembodiments, the obturation material in the reservoir 27 is in aflowable state, and high pressure fluid can pass through the supply line26 and can drive the flowable obturation material from the reservoir 27,through the supply line 26, and out into the treatment region by way ofthe guide tube 21 and opening(s) 42. In other arrangements, thepressurized fluid can drive a plunger (see FIGS. 5A-5B), which can causethe obturation material to flow into the treatment region through theguide tube 21 and opening(s) 42. Once the obturation material fills thetreatment region, the obturation material can be hardened or cured inany suitable manner.

It should be appreciated that any suitable obturation material in itsflowable state may be used to fill or obturate the treatment region ofthe tooth, including any of the obturation materials described herein.For example, the obturation material in its flowable state may have aviscosity and various other fluid properties that are selected to form afluid jet when passing through an orifice near a proximal end of theguide tube 21. In some embodiments, the obturation material can comprisea powder, solid, or semi-solid material that can be dissolved in asuitable liquid (e.g., the pressurized liquid that is passed through thesupply line 26 to drive the obturation material to the guide tube 21 andtooth), resulting in a flowable obturation material. For example, watercan be driven through the high pressure supply line 26. When the switch25 is switched to the obturation mode 25B, the water can mix, dissolve,or otherwise carry a base obturation material (such as a powder) to thetreatment region. In other embodiments, the obturation material may bein a flowable state when stored in the reservoir 27 of the handpiece 3A.

The handpiece 3A can be used in any suitable dental cleaning treatment.For example, the handpiece 3A can be used to clean a root canal of thetooth. In such arrangements, the sealing cap 40 can be sized and shapedto be positioned against an occlusal surface of the tooth, and thepressure wave generator 5 can be disposed inside or outside the toothchamber. Cleaning fluids can be used to form a liquid jet to clean theroot canal spaces, tubules, and tiny cracks and spaces of the interiorof the tooth. Once the root canal is cleaned, the clinician can switchfrom the cleaning mode 25A on the handpiece 3A to the obturation mode25B. Additional details of dental platforms for root canal treatmentsmay be found throughout U.S. Patent Publication No. US 2012/0237893,filed on Oct. 21, 2011, which is incorporated by reference herein in itsentirety and for all purposes.

In other arrangements, the handpiece 3A can be used to clean a cariousregion of a tooth and to fill the cleaned region. Suitable sealing caps40 and/or handpieces 3A that may be used to clean a carious region ofthe tooth may be found at least in FIGS. 1A-9B and the associateddisclosure of International Application Publication No. WO 2013/142385,which is incorporated by reference herein in its entirety and for allpurposes. In addition, the handpiece 3A can be used to clean undesirabledental deposits (such as plaque, calculus, biofilms, etc.) and fill orrepair the cleaned regions if desired or needed. For example, suitablearrangements for cleaning undesirable dental deposits are disclosed inU.S. Patent Publication No. US 2014/0099597, which is incorporated byreference herein in its entirety and for all purposes. Still othertreatment systems for treating root canals (including obturation systemsusing pressure wave generators) are disclosed in U.S. patent applicationSer. No. 14/137,937, filed Dec. 20, 2013, which is incorporated byreference herein in its entirety and for all purposes.

Advantageously, the clinician can use a single instrument (e.g., thehandpiece 3) to clean and fill the treatment tooth, which may reduceexpenses, simplify the treatment procedure, and reduce treatment times.The pressure wave generator 5 can surprisingly generate pressure wavesat the treatment site using cleaning fluids when in the cleaning mode25A and using a flowable obturation material when in the obturation orfilling mode 25B. For example, the clinician can prepare the tooth for acleaning procedure and can switch the handpiece 3A to the cleaning mode.The clinician can use the handpiece 3A to clean the tooth, e.g., withthe pressure wave generator 5. The pressure wave generator 5 cangenerate pressure waves such that the cleaning fluid and associatedfluid dynamics interact with diseased materials throughout the treatmentregion (e.g., a root canal system, a carious region, undesirable dentaldeposits on an outer surface of the tooth, etc.), even in tiny spacesand cracks, to substantially clean the entire treatment region.

Once the tooth is cleaned, the clinician can switch the handpiece 3Afrom the cleaning mode 25A to the obturation mode 25B. The clinician canactivate the handpiece 3A and/or console 2 to obturate the tooth. Thepressure wave generator 5 can generate pressure waves such that theflowable obturation material is flowed into even tiny spaces and cracksin the treatment region to substantially fill or obturate the treatmentregion. Thus, the embodiments disclosed herein can advantageously cleanand fill a treatment region using a pressure wave generator 5, which maybe disposed in or coupled with a single treatment handpiece 3A. In theembodiment of FIGS. 4A-4B, the cleaning fluids and obturation materialcan flow through the same opening(s) 42 in the guide tube 21.

Furthermore, providing the obturation reservoir 27 in the handpiece 3A(rather than in the console or other components of the system) mayfacilitate more effective purging or cleaning of the console 2. Forexample, since the obturation material is stored in the handpiece 3A inthe embodiment of FIGS. 4A-4B, the obturation material does notcontaminate or clog the console 2 or other components between thehandpiece 3A and console 2.

FIG. 5A is a schematic side view of a treatment handpiece 3A configuredto deliver a flowable obturation or filling material to a treatmentregion of a tooth. FIG. 5B is a schematic side cross-sectional view ofthe handpiece 3A shown in FIG. 5A. Unless otherwise noted, referencenumerals used in FIGS. 5A-5B may correspond to components similar to orthe same as similarly-numbered components in FIGS. 4A-4B. For example,the handpiece 3A of FIGS. 5A-5B includes a pressure wave generator 5 anda sealing cap 40 at a distal portion 19 of the handpiece 3A. Thepressure wave generator 5 can comprise a fluid jet device including anozzle (not shown), a guide tube 21, one or more openings 42 in theguide tube 21, and an impingement surface 33 at a distal end of theguide tube 21. A suction port 43 can fluidly communicate with a wasteline 44 configured to convey waste fluids to a waste collection system.An interface member 4 can connect the handpiece 3A to one or moreconduits coupled with the console 2.

The handpiece 3A illustrated in FIGS. 5A-5B can include a fluid supplyline 26 extending from the console 2 to an obturation reservoir 27A. Theobturation reservoir 27A may be at least partially filled with anobturation material (or a base material that, when mixed with a liquid,forms a flowable obturation material). A plunger 29 or piston can bedisposed in the reservoir 27A. Pressurized fluid (e.g., air, water,etc.) can pass through the supply line 26 and can drive the plunger 29distally. The plunger can drive the obturation material distally throughthe supply line 26 to the guide tube 21. The obturation material caninteract with fluids in the chamber 6, and pressure waves may begenerated. The flowable obturation material can flow out of the guidetube 21 through the opening(s) 42 and can fill the treatment region,including tiny cracks and spaces in the tooth. The obturation materialcan be hardened or cured to prevent bacteria or other undesirablematerials from forming in the treatment region.

The handpiece 3A illustrated in FIGS. 5A-5B does not include a switchthat changes the handpiece to a cleaning mode. However, it should beappreciated that the plunger 29 shown in FIG. 5B can be used with thereservoir 27 of FIGS. 4A-4B in a multi-mode handpiece 3A that includesboth a cleaning mode and a filling or obturation mode. The pressurizedfluid that drives the piston or plunger 29 can be pressurized using thepressurization system described above with respect to U.S. applicationSer. No. 14/172,809 and U.S. Patent Publication No. US 2012/0237893,each of which is incorporated by reference herein.

FIG. 6A is a schematic side view of a handpiece 3A having a cleaningmode and an obturation or filling mode. FIG. 6B is a schematic sidecross-sectional view of the handpiece 3A shown in FIG. 6A. The handpiece3A shown in FIGS. 6A-6B can advantageously be configured to clean atooth when the handpiece 3A is in the cleaning mode and to obturate orfill the tooth when the handpiece is in the obturation mode. Unlessotherwise noted, reference numerals used in FIGS. 6A-6B may correspondto components similar to or the same as similarly-numbered components inFIGS. 4A-5B. For example, the handpiece 3A of FIGS. 6A-6B includes apressure wave generator 5 and a sealing cap 40 at a distal portion 19 ofthe handpiece 3A. The pressure wave generator 5 can comprise a fluid jetdevice including a nozzle (not shown), a guide tube 21, one or moreopenings 42 in the guide tube 21, and an impingement surface 33 at adistal end of the guide tube 21. A suction port 43 can fluidlycommunicate with a waste line 44 configured to convey waste fluids to awaste collection system. An interface member 4 can connect the handpiece3A to one or more conduits coupled with the console 2. The console caninclude high pressure pumps for pressurizing the obturation material anda degassing apparatus for degassing the obturation material. Additionaldetails of such a console may be found in U.S. patent application Ser.No. 14/172,809, filed on Feb. 4, 2014, entitled “DENTAL TREATMENTSYSTEM,” which is incorporated by reference herein in its entirety andfor all purposes.

The handpiece 3A can also include a high pressure supply line 26extending from the console 2 to the interface member 4 and into thehandpiece 3A. As explained with respect to FIGS. 4A-4B and 5A-5B, apressurization system (e.g., high pressure pump) in the console 2 canpressurize suitable fluids, which are driven distally to the handpiece3A and guide tube 21 by way of the supply line 26. As with theembodiment of FIGS. 4A-4B, the system can have a cleaning mode, in whichthe handpiece 3A is configured to clean the treatment region, and anobturation or filling mode, in which the handpiece is configured todeliver a flowable obturation or filling material to the treatmentregion. However, unlike the embodiment of FIGS. 4A-4B, in the embodimentof FIGS. 6A-6B, the modes can be switched upstream or proximal thehandpiece 3A.

For example, the console 2 can include a switch (which may be similar tothe switch 25 shown in FIG. 4B) that switches between the cleaning modeand the obturation mode. In various embodiments, the console 2 caninclude a controller (e.g., including a processor) and non-transitorymemory that includes software instructions stored thereon that, whenexecuted by the controller, switches between the cleaning and filling orobturation mode. When in the cleaning mode, cleaning fluids can bepassed along the supply line 26 to the guide tube 21 to clean thetreatment region of the tooth, as explained above with respect to FIGS.4A-4B. When the clinician is finished cleaning the treatment region ofthe tooth, the clinician can switch to the obturation or filling mode,e.g., using the console 2. As shown in FIG. 6B, an obturation reservoir27B or 27C can be disposed at any suitable portion of the fluid pathway.In some embodiments, for example, the obturation reservoir 27B can bedisposed at or in the console 2. In other arrangements, the obturationreservoir 27C may be disposed along a conduit 34, or along any otherportion of the fluid pathway, that extends between the handpiece 3A andthe console 2.

When in the obturation or filling mode, flowable obturation material canflow from the reservoir 27B or 27C and through the supply line 26 to theguide tube 21. The flowable obturation material can flow outwardly tothe treatment region through the opening(s) 42 to fill the treatmentregion. The obturation material can be driven distally in any suitablemanner. For example, in some embodiments, fluid (such as air, water,etc.) can be pressurized and can dissolve, mix with, or otherwiseinteract with the obturation material. The pressurized fluid can carrythe obturation material to the treatment region by way of the supplyline 26. In other embodiments, the pressurized fluid can drive a plunger(such as the plunger 29 or piston shown in FIG. 5B) to drive theobturation material to the treatment region.

Accordingly, the obturation or filler reservoir, e.g., the componentthat contains the obturation or filler material, may be providedupstream of and/or proximal the handpiece 3A in some embodiments, andcan be flowed downstream or distally by way of the pressurized fluid,whether directly or indirectly using a plunger. Furthermore, thehandpiece 3A can be used in both cleaning procedures and obturation orrestoration procedures, which can simplify treatment procedures and/orreduce costs.

FIG. 6C is a side cross-sectional view of a handpiece 3A configured tocouple to a console 2 by way of an interface member 4 and a cartridge601 configured to be disposed between the interface member 4 and theconsole 2. The handpiece 3A shown in FIGS. 6A-6B can advantageously beconfigured to clean a tooth when the handpiece 3A is in the cleaningmode and to obturate or fill the tooth when the handpiece is in theobturation or filling mode. Unless otherwise noted, reference numeralsused in FIG. 6C may correspond to components similar to or the same assimilarly-numbered components in FIGS. 6A-6B. The handpiece 3A of FIG.6C includes a pressure wave generator 5 and a sealing cap 40 at a distalportion 19 of the handpiece 3A. The pressure wave generator 5 cancomprise a fluid jet device including a nozzle (not shown), a guide tube21, one or more openings 42 in the guide tube 21, and an impingementsurface 33 at a distal end of the guide tube 21. A suction port 43 canfluidly communicate with a waste line 44 configured to convey wastefluids to a waste collection system. An interface member 4 can connectthe handpiece 3A to one or more conduits 34 coupled with the console 2.

The handpiece 3A can also include a high pressure supply line 26extending from the console 2 through the conduits 34 (which may comprisea hose) to the interface member 4 and into the handpiece 3A. Asexplained with respect to FIGS. 4A-4B and 5A-5B, a pressurization system(e.g., high pressure pump) in the console 2 can pressurize suitablefluids, which are driven distally to the handpiece 3A and guide tube 21by way of the supply line 26. As with the embodiment of FIGS. 4A-4B, thesystem can have a cleaning mode, in which the handpiece 3A is configuredto clean the treatment region, and an obturation or filling mode, inwhich the handpiece is configured to deliver a flowable obturation orfilling material to the treatment region.

A reservoir 27G can also be provided to store and/or supply filling orobturation material to the handpiece 3A and treatment region. However,in the embodiment illustrated in FIG. 6C, the reservoir 27G can bedisposed in or on a cartridge 601 that is disposed proximal thehandpiece 3A. As shown in FIG. 6C, the cartridge 601 can connect to adistal portion of the interface member 4, which couples with the console2 by way of conduit 34 (e.g., a high-pressure hose). Similarly, thehandpiece 3A can connect to a distal portion of the cartridge 601. Thus,in some embodiments, the cartridge 601, which can include or be coupledwith the reservoir 27G of filling or obturation material, can bedisposed between the handpiece 3A and the interface member 4.

In some embodiments, the cartridge 601 can be removably engaged with theinterface member 4. For example, prior to a cleaning procedure, theclinician can connect the handpiece 3A to the interface member 4 (e.g.,using a suitable connecting mechanism) to enable fluid communicationbetween the console 2 and the handpiece 3A. The clinician can activatethe cleaning procedure (e.g., at the console 2), and cleaning fluids canpass through the supply line 26 from the console 2, through the conduit34 and interface member 4, and into the handpiece 3. The cleaning fluidscan clean the treatment region of the tooth as explained herein.

After cleaning, the clinician can begin a filling or obturationprocedure by inserting the cartridge 601 between the handpiece 3A andinterface member 4. For example, after removing the handpiece 3A fromthe interface member 4, the clinician can connect the cartridge 601 tothe interface member 4, and can connect the handpiece 3A to the distalportion of the cartridge 601. Thus, in various arrangements, thehandpiece 3A and cartridge 601 can have the same connectingconfiguration. For example, the proximal portion of the handpiece 3A caninclude connectors similar to those on the proximal portion of thecartridge 601, such that both the cartridge 601 and the handpiece 3A canconnect to the interface member 4. Further, the distal portion of theinterface member 4 and the distal portion of the cartridge 601 caninclude similar connectors such that the handpiece 3A can connect to thecartridge 601. In some embodiments, the same handpiece 3A can be used toboth clean and fill the treatment region. In other embodiments,different handpieces 3A can be used to clean and fill the tooth.

In other embodiments, the cartridge 601 may be secured or fixed relativeto the interface member 4 such that the cartridge 601 remains coupledwith the interface member 4. In such arrangements, the clinician canconnect the handpiece 3A to the cartridge 601 (which is alreadyconnected to the interface member 4), and can conduct a cleaningprocedure. After cleaning, the clinician can activate a switch on thecartridge 601 to switch from a cleaning mode to a filling or obturationmode. The switch on the cartridge 601 may be the same as or similar tothe switch 25 shown in FIG. 4B. In such embodiments, the clinician maynot remove the handpiece 3A between cleaning and filling the treatmentregion. Further, although the interface member 4 and cartridge 601 areshown as separate components, it should be appreciated that, in someembodiments, the cartridge 601 and interface member 4 can be combinedinto a single unit.

FIG. 6D is a schematic, cross-sectional magnified view of a cartridge601 disposed proximal a handpiece 3A. The cartridge 601, handpiece 3A,conduit 34, and supply line 26 may be similar to or the same assimilarly-numbered components described above with respect to FIGS.4A-6C. Although the interface member 4 is not illustrated in FIG. 6D, asexplained above with respect to FIG. 6C, the interface member 4 may alsobe disposed between the cartridge 601 and the conduit 34. In someembodiments, the cartridge 601 is removable from the conduit 34 and/orthe interface member 4. In other embodiments, the cartridge 601 may besecured or fixed to the conduit 34 and/or interface member 4. In FIG.6D, the cartridge 601 can couple to conduit 34 by way of a firstconnector 603. The first connector 603 may be the same as or similar tothe interface member 4 described herein, or the first connector 603 mayinclude different connections for coupling with the conduit 34. A secondconnector 602 can connect the cartridge 601 with the handpiece 3A. Theconnector 602 can be separate from the handpiece 3A and cartridge 601,or the connector 602 can be coupled to or formed with either thehandpiece 3A or the cartridge 601.

As with FIG. 6C, the cartridge 601 can comprise a reservoir 27G forstoring and/or supplying the obturation or filling material to thehandpiece 3A and treatment region. For example, in some embodiments, thereservoir 27G can comprise a volume or container that stores the fillingmaterial. However, if a container or vessel that encloses a large,enclosed volume is used to store the filling material, then thecontainer may be subject to high pressures. If a relatively large amountof filling material is pressurized (e.g., by way of the high pressuresupply line 26) and stored in the container, then the resulting highpressures may damage the container or cause the container to fail orrupture. Thicker walls or improved container designs may be suitable,however, such solutions may increase the cost or complexity of thecartridge 601 and reservoir 27G.

Accordingly, in some embodiments, the cartridge 601 can comprise areservoir 27G in which the supply line 26 is coiled within or on thecartridge 601 or other type of storage or supply device. As shown inFIG. 6D, the high pressure supply line 26 can pass from the console 2,through the conduit 34, and into the cartridge 601. The portion of thesupply line 26 passing in the conduit 34 may be uncoiled. However, thesupply line 26 can be formed into a coiled portion 626 at the cartridge601. Thus, at the cartridge 601 (e.g., within the cartridge 601), thesupply line 26 can be deformed to form multiple coils. The use ofmultiple coils at the cartridge 601 can enable the storing or supply ofa relatively high volume of filling material, as compared with anuncoiled supply line. For example, coiling the supply line 26 caneffectively increase the length of supply line within the cartridge 601,enabling the coiled portion 626 of the supply line 26 to store or supplya higher volume of filling material. Furthermore, the high pressureimparted on the supply line 26 is distributed across the relativelylarge internal surface area provided by the coiled portion 626, whichcan reduce the load on the supply line 26 and reduce or prevent damageor failure to the cartridge 601 or supply line 26. The supply line 26may be straightened or uncoiled distal the cartridge 601 when the supplyline 26 passes through the handpiece 3A.

It should be appreciated that the cartridge 601 and/or reservoir 27Gshown in FIG. 6D with the coiled portion 626 of the supply line 26 maybe used in any of the embodiments disclosed herein. For example, thereservoir 27 of FIG. 4B may similarly comprise a coiled portion of thesupply line 26. Similarly, reservoirs 27B and 27C of FIG. 6B may alsocomprise a coiled portion of the supply line 26.

FIG. 7A is a schematic side view of a handpiece 3A having a removableobturation reservoir 27D. FIG. 7B is a schematic side cross-sectionalview of the handpiece 3A shown in FIG. 7A. The handpiece 3A shown inFIGS. 7A-7B can advantageously be configured to be reused in multipleobturation treatments. Unless otherwise noted, reference numerals usedin FIGS. 7A-7B may correspond to components similar to or the same assimilarly-numbered components in FIGS. 4A-6D. For example, the handpiece3A of FIGS. 7A-7B includes a pressure wave generator 5 and a sealing cap40 at a distal portion 19 of the handpiece 3A. The pressure wavegenerator 5 can comprise a fluid jet device including a nozzle (notshown), a guide tube 21, one or more openings 42 in the guide tube 21,and an impingement surface 33 at a distal end of the guide tube 21. Asuction port 43 can fluidly communicate with a waste line 44 configuredto convey waste fluids to a waste collection system. An interface member4 can connect the handpiece 3A to one or more conduits coupled with theconsole 2.

The handpiece 3A can also include a high pressure supply line 26extending from the console 2 to the interface member 4 and into thehandpiece 3A. As explained with respect to FIGS. 4A-6B, a pressurizationsystem (e.g., high pressure pump) in the console 2 can pressurizesuitable fluids, which are driven distally to the handpiece 3A and guidetube 21 by way of the supply line 26. Unlike the embodiments of FIGS.4A-6B, however, the handpiece 3A can include a compartment 31 sized andshaped to receive a removable obturation reservoir 27D. For example, theobturation reservoir 27D may be provided separately from the handpiece3A. The clinician can insert the reservoir 27D into the compartment 31prior to an obturation or filling procedure. One or more connectors 35can be provided in the handpiece 3A to secure the reservoir 27D to thecompartment 31 and to provide fluid communication between the reservoir27D and the supply line 26.

During an obturation or filling procedure, as explained above, theclinician can activate the handpiece 3A (e.g., using the console 2) todrive a pressurized fluid along the supply line 26 to the reservoir 27D.In the embodiment of FIGS. 7A-7B, the pressurized fluid can pressagainst a plunger 29 or piston, which can drive the obturation orfilling material along the supply line 26 to the guide tube 21 and thetreatment region. In other arrangements, as explained above, thepressurized fluid can directly drive the obturation material and/or canmix or dissolve the obturation material to cause the obturation materialto be flowable. Once the filling procedure is complete the clinician canremove the obturation reservoir 27D from the handpiece 3A and can reusethe handpiece 3A in a subsequent procedure.

The handpiece 3A illustrated in FIGS. 7A-7B does not show a switch thatchanges the handpiece to a cleaning mode. However, it should beappreciated that the reservoir 27 shown in the multi-mode handpiece 3Aof FIG. 4B can instead be configured to be removable, similar to theembodiment shown in FIG. 7B. Thus, in some embodiments, a multi-modehandpiece 3A may be reused for both cleaning and obturation procedures,provided that adequate cleaning and/or sanitation safeguards aremaintained. The pressurized fluid that drives the piston or plunger 29can be pressurized using the pressurization system described above withrespect to U.S. application Ser. No. 14/172,809 and U.S. PatentPublication No. US 2012/0237893, each of which is incorporated byreference herein. It should further be appreciated that the reservoir27D shown in FIG. 7B can include a coiled portion 626 of the supply line26, as shown and described with relation to FIG. 6D.

FIG. 8A is a schematic side cross-sectional view of a handpiece 3Aconfigured to deliver a first composition (e.g., a gelifying material)and a second composition (e.g., a gelifying initiator) to a treatmentregion of a tooth to obturate or fill the treatment region of the tooth,according to one embodiment. Unless otherwise noted, reference numeralsused in FIG. 8A may correspond to components similar to or the same assimilarly-numbered components in FIGS. 4A-7B. For example, the handpiece3A of FIG. 8A includes a sealing cap 40 at a distal portion 19 of thehandpiece 3A and a suction port 23 in fluid communication with a wasteline 44 configured to convey waste fluids to a waste collection system.An interface member 4 can connect the handpiece 3A to one or moreconduits coupled with the console 2.

Unlike the embodiments of FIGS. 4A-7B, however, the embodiment of FIG.8A includes a first high pressure fluid supply line 26A and a secondhigh pressure fluid supply line 26B extending from the console 2 to thedistal portion 29 of the handpiece 3A. The first and second supply lines26A, 26B can be configured to deliver two materials that, when mixed inthe tooth or just prior to entering the tooth, form a gel that issuitable for filling the treatment region of the tooth. For example, agelifying initiator can be conveyed along the first supply line 26A tothe distal portion 19 of the handpiece 3, and a gelifying obturationmaterial can be delivered along the second supply line 26B to the distalportion 19 of the handpiece 3A. The gelifying initiator and obturationmaterial can be stored in reservoirs located at the console 2 (oranywhere along the pathway between the console 2 and the handpiece 3A,and suitable pressurization systems (such as the pumps disclosed herein)can drive the initiator and obturation material to the handpiece 3A. Insome embodiments, the reservoirs can comprise a coiled portion of thesupply lines 26A, 26B. Although gelifying initiators and materials aredisclosed with respect to FIGS. 8A-8D, it should be appreciated that anysuitable combination of compositions may be used, including materialsconfigured to be cured, hardened, etc.

The gelifying material can comprise any suitable obturation materialthat turns into a gel when it interacts with a gelifying initiator. Forexample, as explained herein, a sodium Alginate solution can gelify uponexposure to calcium or calcium containing compounds (e.g., CaCl₂)). Insuch an arrangement, the sodium Alginate may act as the gelifyingmaterial, and the calcium-containing material may act as the gelifyinginitiator. It should be appreciated that sodium Alginate andcalcium-containing materials are just a few illustrative examples. Anyother suitable gelifying materials and initiators may be used in theembodiments disclosed herein, including additional gel arrangementsdisclosed herein. Furthermore, although the materials are described asgelifying initiators and materials, it should be appreciated that anyother combination of materials can be mixed at the treatment region ofthe tooth. In addition, although two supply lines are illustrated formixing two materials in FIG. 8A, it should be appreciated thatadditional supply lines may be provided to mix or cause more than twomaterials (e.g., three, four, five, or more) to interact at thetreatment region. Furthermore, it should be appreciated that anysuitable combination of materials other than gelifying materials may beused in the embodiments of FIGS. 8A-8D.

The gel initiator can be conveyed into the treatment region of the toothby way of a first inlet 21A in fluid communication with the first supplyline 26A. The gelifying obturation material can be conveyed into thetreatment region of the tooth by way of a second inlet 21B in fluidcommunication with the second supply line 26B. The gelifying initiatorcan interact with the gelifying obturation material at the treatmentregion (e.g., within the tooth chamber or near a carious region of thetooth), and the resulting obturation gel can fill the treatment region(e.g., a root canal or a cleaned carious region), including small spacesand cracks in the tooth. Although a pressure wave generator is notillustrated in FIG. 8A, it should be appreciated that any suitablepressure wave generator 5 (such as a fluid jet) can also be used toassist in filling the treatment region. Thus, in FIG. 8A, the componentsof the obturation material can be supplied to the tooth by inlets 21A,21B, and the pressure wave generator can be activated to enhance thefilling. Although the embodiment of FIG. 8A has been disclosed withreference to a gelifying base material and a gelifying initiator, itshould be appreciated that the handpiece 3A of FIG. 8A can be used withany suitable combination of components for an obturation material.

FIG. 8B is a schematic side cross-sectional view of a handpiece 3Aconfigured to deliver a first composition (e.g., a gelifying material)and a second composition (e.g., a gelifying initiator) to fill atreatment region of a tooth, according to another embodiment. Unlessotherwise noted, reference numerals used in FIG. 8B may correspond tocomponents similar to or the same as similarly-numbered components inFIG. 8A. For example, the handpiece 3A of FIG. 8B includes a sealing cap40 at a distal portion 19 of the handpiece 3A and a suction port 43 influid communication with a waste line 44 configured to convey wastefluids to a waste collection system. An interface member 4 can connectthe handpiece 3A to one or more conduits coupled with the console 2.

The handpiece 3A can also include a first supply line 26A that conveys agelifying initiator and a second supply line 26B that conveys agelifying obturation material. A first inlet 21A can supply thegelifying initiator to the treatment region and a second inlet 21A cansupply the gelifying obturation material to the treatment region. Thegelifying initiator can interact with the base gelifying obturationmaterial to form a gel sufficient to fill the treatment region of thetooth, including small spaces and cracks of the tooth. However, unlikethe embodiment of FIG. 8A, the handpiece 3A shown in FIG. 8B can includea gelifying initiator reservoir 27E and a gelifying obturation materialreservoir 27F that are loaded on or coupled with the handpiece 3A.Plungers 29 can be driven by pressurized fluid to drive the gelifyinginitiator from the reservoir 27E and the gelifying obturation materialfrom the reservoir 27F. The reservoirs 27E, 27F may be permanentlyformed with or coupled to the handpiece 3A in some arrangements. Inother arrangements, the reservoirs 27E, 27F may be removably coupledwith the handpiece 3, similar to the arrangement described above withrespect to FIGS. 7A-7B. In some embodiments, a pressure wave generatorcan be activated during or after the supply lines 26A, 26B deliver thematerials to the tooth to enhance filling. Although the embodiment ofFIG. 8B has been disclosed with reference to a gelifying base materialand a gelifying initiator, it should be appreciated that the handpiece3A of FIG. 8B can be used with any suitable combination of componentsfor an obturation material. Further, although the reservoirs 27E, 27Fare illustrated as including plungers 29, it should be appreciated thatany suitable reservoir can be used, including a reservoir that comprisesa coiled portion of the supply lines 26A, 26B.

FIG. 8C is a schematic side cross-sectional view of a handpiece 3Aconfigured to deliver multiple components of an obturation material tothe treatment region. Unless otherwise noted, reference numerals used inFIG. 8C may correspond to components similar to or the same assimilarly-numbered components in FIGS. 8A-8B. For example, the handpiece3A of FIG. 8C includes a sealing cap 40 at a distal portion 19 of thehandpiece 3A and a suction port 43 in fluid communication with a wasteline 44 configured to convey waste fluids to a waste collection system.An interface member 4 can connect the handpiece 3A to one or moreconduits coupled with the console 2.

The handpiece 3A can also include a first supply line 26A that conveys agelifying initiator and a second supply line 26B that conveys agelifying obturation material. The first and second supply lines 26A,26B can extend from the console 2 to the handpiece 3A, as explainedabove with respect to FIG. 8A. A reservoir may store the fillingmaterial and can be disposed in the console 2, in the handpiece 3A, orbetween the handpiece 3A and console 2. In some embodiments, thereservoir can comprise a coiled portion of the supply lines 26A, 26B, asdescribed above with respect to FIG. 6D. Unlike the embodiment of FIGS.8A-8B, however, the first and second supply lines 26A, 26B can join at ajunction 26′. The respective materials that pass through the supplylines 26A, 26B can be mixed at the junction 26′ and can pass along acommon supply line 26 to a guide tube 21 of a pressure wave generator 5.The gelifying initiator can interact with the base gelifying obturationmaterial to form a gel sufficient to fill the treatment region of thetooth, including small spaces and cracks of the tooth. The mixedmaterial can pass along the guide tube 21 and can form a jet afterpassing through an orifice. The jet of obturation material can enter thetreatment region through the openings 42. An impingement surface 33 candeflect the jet to prevent damage to the anatomy.

As shown in FIG. 8C, the pressure wave generator 5 can therefore delivera combination of materials to the treatment region. Because the twocomponents (e.g., the gelifying initiator and the base material) aremixed in the handpiece 3A just prior to entering the treatment region,the hardening or gelification process may not have been completed, andthe obturation material may be sufficiently flowable to fill thetreatment region. As explained herein, the pressure wave generator 5 canbe activated to substantially fill the treatment region, including smallspaces of the tooth. Further, although the embodiment of FIG. 8C hasbeen disclosed with reference to a gelifying base material and agelifying initiator, it should be appreciated that the handpiece 3A ofFIG. 8C can be used with any suitable combination of components for anobturation material.

FIG. 8D is a schematic side cross-sectional view of a handpiece 3Aconfigured to deliver multiple components of an obturation material tothe treatment region. Unless otherwise noted, reference numerals used inFIG. 8D may correspond to components similar to or the same assimilarly-numbered components in FIGS. 8A-8C. For example, the handpiece3A of FIG. 8D includes a sealing cap 40 at a distal portion 19 of thehandpiece 3A and a suction port 43 in fluid communication with a wasteline 44 configured to convey waste fluids to a waste collection system.An interface member 4 can connect the handpiece 3A to one or moreconduits coupled with the console 2. A reservoir may store the fillingmaterial and can be disposed in the console 2, in the handpiece 3A, orbetween the handpiece 3A and console 2.

The handpiece 3A can also include a first supply line 26A that conveys agelifying initiator and a second supply line 26B that conveys agelifying obturation material. The first and second supply lines 26A,26B can extend from the console 2 to the handpiece 3A, as explainedabove with respect to FIG. 8A. As shown in FIG. 8D, a first pressurewave generator 5A and a second pressure wave generator 5B can bedisposed near the distal portion 19 of the handpiece 3A. The firstpressure wave generator 5A can comprise a first guide tube 21A in fluidcommunication with the first supply line 26A, and the second pressurewave generator 5B can comprise a second guide tube 21B in fluidcommunication with the second supply line 26B. Components of theobturation material can pass along the supply lines 26A, 26B to therespective guide tubes 21A, 21B. Upon passing through an orifice (notshown), two jets can be formed that are conveyed along the guide tubes21A, 21B. The components of the obturation material (e.g., the gelifyinginitiator and the gelifying obturation material) can enter the treatmentregion by way of first and second openings 42A, 42B, respectively.Impingement surfaces 33A, 33B can prevent the jet from impacting theanatomy directly. In the embodiment of FIG. 8D, the pressure wavegenerators 5A, 5B can generate pressure waves that cause the twocomponent materials to mix at the treatment region and to substantiallyfill the treatment region. Further, although the embodiment of FIG. 8Dhas been disclosed with reference to a gelifying base material and agelifying initiator, it should be appreciated that the handpiece 3A ofFIG. 8D can be used with any suitable combination of components for anobturation material.

III. Examples of Filling Materials and Methods

Various embodiments disclosed herein may be used to obturate a rootcanal of a tooth after cleaning, and/or to fill a portion of a treatmentregion after cleaning, e.g., a treated carious region. As explainedherein, various methods can be used to clean a treatment region of atooth. For example, in some embodiments, a pressure wave generator 5 canbe used to clean diseased materials, bacteria, and other undesirablematerials from the root canal of the tooth. In other embodiments, thepressure wave generator 5 can clean a carious region from an outersurface of the tooth. When the treatment region (e.g., root canal,carious region, etc.) is substantially clean, the clinician can obturateor fill the treatment region with a suitable obturation material. Forexample, in a root canal treatment, the clinician may fill the canalswith the obturation material in order to prevent bacteria or otherundesirable materials from growing (or otherwise forming) in the canalspaces after treatment. Accordingly, to protect the long-term health ofthe tooth, it can be advantageous to substantially fill the canal spacesof the tooth, including the major canal spaces as well as minor cracksand spaces in the tooth. The filling or obturation material can be curedor hardened to form the final material. Indeed, it should be appreciatedthat setting, curing, hardening, etc. may all refer to processes bywhich initial components are transformed into the final material. Itshould be appreciated that each of the obturation materials (and alsothe handpieces) disclosed herein may be used in conjunction with fillingroot canals after root canal treatments and/or with filling treatedcarious regions after treatment. Thus, the use of the term “obturationmaterial” should be understood to mean a material that is configured tofill root canals and/or treated carious regions of the tooth. Similarly,as used herein, obturating or filling a treatment region should beunderstood to mean a procedure in which a treatment region is filled orrestored, e.g., filling a root canal or a treated carious region of atooth.

In some embodiments, a pressure wave generator 5 is used to assist inobturating the treatment region. For example, in some embodiments, theobturation material can be delivered using a needle and pressure drivenmechanism, such as a syringe. In such arrangements, the pressure wavegenerator 5 can be provided separate from the syringe, and can beactivated to assist in causing the obturation material to flow intosmall spaces and cracks of the treatment region. In other embodiments,the clinician can use another type of mechanical device or theclinician's hand to place the material inside the tooth chamber, and thepressure wave generator 5 can be activated to help cause the obturationmaterial to fill the treatment region. In still other embodiments, asuction-based delivery system can apply a negative pressure to the rootcanal space, causing the obturation material to be drawn into the rootcanal spaces. The pressure wave generator 5 can be activated to assistin filling the treatment region. In yet other embodiments, the pressurewave generator 5 can deliver one component of the filler material at ahigh pressure, and another device (such as a syringe or other mechanicaldelivery device) can deliver a second component of the filler materialat any suitable pressure.

In some arrangements, as explained herein, the pressure wave generator 5can act as the delivery device to supply the obturation material to thetreatment region and to cause the obturation material to substantiallyfill the treatment area, e.g., the canal spaces of a root canal. Forexample, in some embodiments, the pressure wave generator can comprise aliquid jet device. The obturation material (which may include one, two,or more compositions) may be flowed through a handpiece (see FIGS.4A-8D) under pressure. A liquid jet device at a distal portion of thehandpiece can include a jet-forming nozzle or orifice and a guide tubealong which the jet propagates. The obturation material(s) may form aliquid jet upon passing through the liquid jet device. For a particulartype of obturation material, the driving pressure and orifice/nozzlediameter can be selected such that the obturation or filling materialforms a fluid jet. One or more openings in the guide tube can allow theobturation material(s) to flow into the treatment region (e.g., rootcanal) to supply the obturation material(s) to the treatment region. Thejet of obturation material can pass through fluid in the treatmentregion (e.g., other flowable obturation material, other treatmentfluids, etc.), which may generate pressure waves in the fluid. Asexplained herein, the generated pressure waves can assist in propagatingthe obturation material throughout the treatment region, including,e.g., small spaces and cracks in the tooth.

In addition, the handpiece 3 can be used to deliver multiple materials,or a mixture of multiple materials, to the treatment region (e.g., rootcanal). For example, in some embodiments, multiple materials can bemixed at the handpiece or upstream of the handpiece. The resultingmixture can be supplied to the treatment region by the handpiece (e.g.,by the pressure wave generator). In other arrangements, multiplematerials can be delivered to the treatment region and can be mixed atthe treatment region, such as within the tooth.

As explained above, the pressure wave generator can be activated toassist in causing obturation material to flow throughout the treatmentregion, including into small spaces, cracks, and tubules of the tooth.Moreover, in some arrangements, the pressure wave generator 5 can beactivated to assist in curing or hardening the obturation material. Forexample, in some arrangements, mechanical agitation by the pressurewaves can assist in hardening the obturation material. In otherarrangements, agitation by the pressure waves can break apart anencapsulating material that covers a particular type of material (suchas ionic particles or compounds, or a polymerization initiator), which,when released, can react with another material (such as a monomer,oligomer, polymer, etc.). The energy delivered by the pressure wavegenerator can be controlled to control the rate of hardening of theobturation material in the tooth or treatment region. Thus, the use of apressure wave generator 5 can assist in ensuring that the entiretreatment region is filled with obturation material, and can also assistin the hardening of the obturation material.

It should be appreciated that the filling material and proceduralparameters for the pressure wave generator 5 may be selected such thatthe filling material is flowable as it fills the canal or treatmentregion, and then once it fills the canals or treatment region, it can behardened. For multiple component mixtures, for example, the reactionrate between the components, the mixing rate of the components, and thefill rate of the filling material can at least in part determine whetherthe obturation is effective. For example, if the fill rate is less thanthe reaction rate, then the composition may harden before filling thetreatment region. If the fill rate is faster than the mixing rate of thetwo components, then an inhomogeneous mixture may result in the canalsor treatment region. Accordingly, it can be important so selectcombinations of compositions such that the material is able to flowfully into the treatment region before it hardens and such that thecompositions mix well before it fills the treatment region and hardens.In addition, for single component materials, the material and curingmethod can be selected such that the filling material does not hardenbefore it fills the treatment region.

A. Non-Limiting Examples of Obturation Materials

Various types of obturation or filling materials may be suitable withthe embodiments disclosed herein. In some embodiments, the obturation orfilling material can comprise two or more components that react with oneanother to form a hardened obturation material. In other embodiments,the obturation or filling material can comprise a composition that iscurable from a flowable state to a hardened state by way of an externaltrigger (e.g., light, heat, etc.). Still other types of obturationmaterials may be hardened by precipitation, by the addition of moisture,by drying or evaporation, or by combination with a catalyst orinitiator.

1. Multi-Component Obturation Materials

Various obturation materials used with the embodiments disclosed hereinmay include two components that are mixed prior to entering the tooth,or that are mixed inside the tooth or at the treatment region. Thecomponents may comprise one or more chemical compounds. For example, afirst, flowable carrier component, X, may act as a flowable carriermaterial and may act to flow through the treatment region to fill thetreatment region (e.g., the root canal system). A second fillercomponent, Y, may comprise a material that is a solid, a semisolid, apowder, a paste, a granular material, a liquid-containing granularmaterial, a solution containing particles (such as nanoparticles), aliquid containing gas, a gas, or any other physical form. In variousarrangements, the first flowable component X may have physicalproperties (such as viscosity) closer to water than the second componentY. In some embodiments, the second flowable component X is configured tobe delivered by way of the pressure wave generator 5 of the handpiece 3,e.g., by way of a high pressure fluid supply line in the handpiece 3.The second filler component Y may be delivered via a separatehigh-pressure line, or by a low pressure line, in the handpiece 3. Forexample, the second filler component Y may be delivered with activepressure or may be driven via suction, for example, by way of thesuction created by the jet in a jet apparatus. The second fillercomponent Y may be delivered by a separate pump or delivery mechanismthat may or may not be synchronized with and/or coupled to the handpiece3. In some embodiments, the second filler component Y may comprise amaterial that is placed into the treatment region by hand, needle, orany other delivery mechanism before, during, or after the introductionof the first flowable component X.

The filler component Y may be mixed with the flowable component X in theconsole 2, somewhere along the high pressure flow path between thehandpiece 3 and the console 2, in the handpiece 3 (e.g., in a reservoiror cartridge within the handpiece 3), or at the treatment region (e.g.,in the tooth chamber or root canals). The flowable component X maydissolve or carry filler material Y with itself into the treatmentregion of the tooth. The filler component Y may be applied directly intothe tooth, and flowable component X may be supplied and flowed throughthe treatment region with the pressure wave generator 5. In someembodiments, the hydroacoustic and hydrodynamic effects created by thepressure wave generator 5 may dissolve or activate filler material Y.Other triggers may also be used, e.g., light, heat, etc. The flowablecomponent X may be sufficiently degassed such that the resulting mixtureof flowable component X and filler component Y is also adequatelydegassed.

The physical properties of the obturation material may be controlledsuch that the obturation material can be delivered into the treatmentregion of the tooth by way of the pressure wave generator 5 to provideadequate filling and sealing before the properties of the obturationmaterial changes and/or before the obturation material sets or is cured.The setting/curing time may be controlled such that adequate mixing isobtained and adequate filling and sealing is obtained before theobturation material sets. In one embodiment, the entire filling processis completed in about 5 seconds or less. In other embodiments it maytake up to about 30 s, 60 s, or 5 minutes for proper and adequatefilling and sealing to occur.

The second fillable component Y may be provided inside a cartridge orreservoir that is disposed in or near the handpiece 3. As explainedabove, the cartridge can be provided at the handpiece 3 or upstream fromthe handpiece 3. The cartridge or reservoir may contain the fillercomponent Y, which may or may not be degassed. In embodiments in whichthe cartridge is upstream of the handpiece 3, the cartridge may providefeatures that allow for sufficient mixing with adequate uniformity ofcomponents X and Y before entering the handpiece. In embodiments inwhich the reservoir or cartridge is disposed in the handpiece 3, thecomponents X and Y can be suitably mixed in the handpiece 3 just priorto being supplied to the treatment region of the tooth. In still otherarrangements, the components X and Y are maintained separate from oneanother in the handpiece 3 and are mixed together at or near thetreatment region of the tooth. In various embodiments, the cartridge orreservoir may be disposable. The handpiece can also be disposable.

2. Other Examples of Multi-Component Obturation Materials

In some embodiments, the filling or obturation material may be hardenedby utilizing a multi-component (e.g., two component) chemically curablesystem. Hardening of such systems may comprise mixing of stoichiometricor approximately stoichiometric relative amounts of initially separatecomponents, herein termed component A and component B, which can thenundergo chemical reactions to form a hardened material. In somearrangements, the mixing of components may be done by volume or othersuitable measure. Mixing may occur immediately prior to delivering thematerial into the root canal system (or other treatment region), ormixing may occur within the root canal system or treatment region aftersimultaneous, consecutive, or alternating delivery of both parts intothe tooth through diffusion. For example, in some embodiments, componentA and component B can be mixed in the handpiece 3 or along the fluidpathway between the handpiece 3 and console 2. The components A and Bcan therefore be delivered as a mixture to the tooth. In otherembodiments, component A and component B can be delivered to the toothalong separate fluid pathways and can be mixed in the tooth. In someembodiments, component A and B can be introduced to the treatment regionconcurrently. In other embodiments, component A can be introduced to thetreatment region, then component B can be introduced to the treatmentregion. In still other embodiments, component A can be delivered to thetooth, then component B can be delivered to the tooth, then component Acan be delivered to the tooth, component B can be delivered to thetooth, and so on, until the treatment region is filled. Any suitableorder or permutation of material delivery may be suitable. Mixing mayalso be assisted by agitation provided by the pressure wave generatorsdisclosed herein.

In some embodiments, the hardening reaction may comprise the addition ofsuitably reactive functional groups of the first component A to strainedcyclic functional groups present in the second component B. Examplesinclude, without limitation, reactions between oxirane or oxetane groupsand nucleophilic functional groups, including the known epoxy-amine andepoxy-thiol systems. In one embodiment, component A may comprise diepoxyfunctionalized prepolymers. The prepolymers can advantageously behydrophilic, which may facilitate penetration of the uncured liquid deepinto small spaces within the root canal system, such as side canals anddentinal tubules. However, hydrophobic prepolymers may also be suitable.The prepolymers may include without limitation poly(alkylene glycol)diglycidyl ether, and may further comprise poly(glycidyl ether)crosslinking prepolymers including without limitation trimethylolpropanetri(glycidyl ether), ethoxylated trimethylolpropane tri(glycidyl ether),pentaerythritol tetra(glycidyl ether), ethoxylated pentaerythritoltetra(glycidyl ether), and the like. Component B may comprisehydrophobic and, advantageously, hydrophilic polyamine compoundsincluding without limitation poly(alkylene oxide) diamines such aspoly(ethylene glycol) di(3-aminopropyl ether). The obturation materialmay further contain radio contrast agents in the form of fine powdersdispersed in part A or part B, or both. Suitable radio contrast agentsinclude without limitation barium sulfate, bismuth oxychloride, bismuthcarbonate, calcium tungstate, zirconium dioxide, ytterbium fluoride, andother suitable agents.

In another embodiment, the hardening reaction may comprise ioniccrosslinking of anionically functionalized polysaccharides withmultivalent cations. Component A may comprise a solution of an anionicpolysaccharide and component B may comprise a solution of salts andpolyvalent metal cations. The solvents in components A and B may beidentical or they may be mutually miscible. One example solvent forcomponents A and B may be water; however, other solvents may also besuitable. In one embodiment, the anionic polysaccharide may be selectedfrom alginic acid and its salts with monovalent cations. Onenon-limiting example is sodium alginate, as explained in more detailbelow. The multivalent cation may be selected from earth alkaline metalsalts or other cations that form stable chelates with the anionicpolysaccharide. In one embodiment, the multivalent cation can bedivalent calcium. Multivalent cations of metals with high atomic numbersmay be added to impart radiopacity. Non-limiting examples of high atomicnumber cations include divalent strontium and barium salts.

In yet another embodiment, the hardening reaction may comprise areaction between acid-dissolvable metal oxide solids and polyacids inthe presence of water. Component A may comprise a metal oxide solid as apowder, dispersed in water, or other, water miscible, liquid. For thepurposes of this disclosure, the term metal oxide is to be understood asbroadly defined to include other basic acid-dissolvable inorganic salts,minerals, compounds, and glasses that may contain anions other thanoxide anions such as phosphate, sulfate, fluoride, chloride, hydroxide,and others. Component B may comprise a solution of a polyacid in wateror other, advantageously water miscible, liquid. An amount of watersufficient to at least partially support the setting reaction can bepresent in part A or part B, or both. The polyacid can undergo anacid-base reaction with the generally basic metal oxide, which may leadto the release of multivalent metal cations that form ionic crosslinkswith the at least partially dissociated anionic polyacid to form astable hardened matrix. Examples for suitable polyacids include withoutlimitation polycarboxylic acids such as poly(acrylic acid),poly(itaconic acid), poly(maleic acid) and copolymers thereof, and mayalso be selected from polymers functionalized with other acidicfunctional groups such as sulfonic, sulfinic, phosphoric, phosphonic,phosphinic, boric, boronic acid groups, and combinations thereof.Examples of suitable basic metal oxides include without limitation zincoxide, calcium oxide, hydroxyapatite, and reactive glasses such asaluminofluorosilicate glasses which may further contain calcium,strontium, barium, sodium, and other metal cations. In one embodiment,radio contrast agents as defined above may further be present incomponent A or component B, or both. In another embodiment, the materialmay further contain a hardenable resin composition that is curable byexposure to actinic radiation such as ultraviolet or visible light. Thepresence of a radiation curable resin may allow the practitioner tocommand cure at least part of the composition following the fillingprocedure to advantageously provide an immediate coronal seal. Theradiation curable resin may be present in component A or component B, orboth.

In yet another embodiment, the hardening reaction may comprise additionpolymerization of silicone prepolymers that proceed with or withoutaddition of catalysts. A non-limiting example of this reaction is ahydrosilylation addition to vinyl groups. Suitable silicone prepolymersmay be selected from poly(diorgano siloxane) additionally substitutedwith reactive functional groups. Poly(diorgano siloxane) prepolymers ofthe general formula Z1-[R1R2SiO2]n-Z2 include without limitationpoly(dialkyl siloxane) wherein R1 and R2 comprise identical or differentalkyl radicals, poly(diaryl siloxane) wherein R1 and R2 compriseidentical or different aryl radicals, and poly(alkyl aryl siloxane)wherein R1 and R2 comprise alkyl and aryl radicals. A suitable,non-limiting example for a poly(dialkyl siloxane) is poly(dimethylsiloxane); however other linear or branched alkyl substituents may besuitable. In one embodiment, component A may comprise vinylfunctionalized silicone prepolymers including without limitationpoly(diorgano siloxane) prepolymers carrying at least one vinyl group.Non-limiting examples are vinyl terminated poly(dimethyl siloxane) whereZ1 and Z2 are vinyl groups, and copolymers of dialkyl siloxane and vinylalkyl or vinyl aryl siloxane where R1 or R2 is a vinyl group in at leastone repeat unit. Component B may comprise hydrosilane functionalizedsilicone prepolymers including without limitation vinyl hydrideterminated poly(dimethyl siloxane) wherein Z1 and Z2 are hydrogen, andcopolymers of dialkyl siloxane and hydro alkyl or hydro aryl siloxanewherein R1 or R2 is hydrogen in at least one repeat unit.Advantageously, the hydrosilane prepolymer can be functionalized with atleast two, three or more hydrosilane groups. A polymerization catalystmay be added to either part A or part B. Examples of suitable catalystsinclude platinum catalysts such as hexachloroplatinic acid or Karstedt'scatalyst (platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxanecomplex).

Optionally, additives such as polymerization mediators and retarders mayfurther be present in component A or component B, or both.Advantageously, the composition may further contain surfactants tofacilitate penetration of the uncured liquid into small spaces withinthe root canal system. In some embodiments, radio contrast agents asdefined above may further be present in component A or component B, orboth. In one embodiment, component A and component B may be non-reactivein the absence of a suitable catalyst. In such an embodiment, componentsA and B may be combined prior to delivery. In some arrangements,components A and B may be stored in combined form for extended periodsof time. The setting reaction may be induced by adding a suitablecatalyst to the composition immediately prior to or following deliveryof the composition into the root canal system, which advantageouslyobviates the mixing of the two components A and B in pre-defined ratiosduring delivery.

3. Gel-Based Obturation Materials

In various embodiments, the filling material used to fill the treatmentregion of a tooth (e.g., a tooth chamber, a root canal system, a treatedcarious region of a tooth) can include a gel-based material such aspolymer molecules dissolved in water or hydrogel. In some arrangements,the polymer molecules can form a gel as soon as the molecules are incontact with water molecules. In various arrangements, other types ofpolymer molecules may form a gel following a trigger when the moleculesare already in an aqueous solution. For example, the trigger cancomprise heat, the addition of a composition having a predetermined pH,and/or chemical reactions between the polymer molecules and a differentcompound (such as a gelifying initiator). In some embodiments, thegel-based obturation materials may also comprise a multi-componentobturation material, e.g., a polymer-ionic compound reaction, apolymer-polymer reaction, etc.

In some embodiments, the gelification (e.g., solidification) of apolymer solution (e.g., sodium alginate) in the presence of ioniccompounds (e.g., calcium) may be used to obturate a root canal system. Aliquid solution of polymers (e.g., sodium alginate) can be deliveredinto the treatment area, e.g. inside the tooth. Once the delivery of thesolution (which may be three-dimensional and/or bubble-free) iscomplete, gelification can be achieved by, for example, providing ioniccompounds to the solution. An ion-based (e.g., calcium-based) liquid maybe delivered, or a calcium-based material (for example calciumhydroxide) may be applied, somewhere inside the tooth (or just prior tobeing delivered to the tooth) to contact the polymer. The calcium inthis material can diffuse into solution and initiate the gelification ofthe material inside the tooth.

The gelification process can occur at different rates as a function ofthe availability of ions to the polymer compound. Gelification timescales can range from a fraction of a second to minutes, hours, etc.During an obturation or filling procedure, it can be important toprecisely control the rate of gelification. For example, if gelificationoccurs too rapidly, then the obturation material may harden before ithas fully filled the treatment region. Furthermore, rapid gelificationmay result in a non-homogenous mixture of materials, which may result ina poor obturation. On the other hand, if gelification occurs too slowly,then the obturation procedure may take too much time, creatingdiscomfort for the patient and reducing efficiency of the treatmentprocedure. Accordingly, it can be desirable to control the rate ofgelification such that the obturation procedure is relatively fast,while also ensuring that the obturation material is substantiallyhomogenous and that the obturation material substantially fills thetreatment region.

In some embodiments, a pressure wave generator can be used to helpcontrol the gelification process. For example, as explained above, thepressure wave generator can cause pressure waves to propagate throughthe obturation material, which can assist in causing the obturationmaterial to flow through substantially the entire treatment region. Forexample, for root canal obturation procedures, the pressure wavegenerator can cause obturation material to flow through the major canalspaces, as well as the tiny cracks and spaces of the tooth. In addition,if the gelifying initiator (e.g., calcium particles or a calciumcompound) is coated with an encapsulant, the pressure wave generator canbe activated to break up the encapsulant to cause the release of thegelifying initiator. The pressure wave generator can be controlled tocause the release of the gelifying initiator at the desired rate. Forexample, if the gelification rate is to be increased, the energysupplied by the pressure wave generator may be increased to increase therate at which the gelifying initiator is released. If the gelificationrate is to be decreased, then the energy supplied by the pressure wavegenerator may be decreased to decrease the rate at which the gelifyinginitiator is released.

In other embodiments, another control mechanism may be the rate of ionsreleased into the solution. For example, the ions can be supplieddirectly by means of concentrated solutions of triggering ions. If theconcentrated solutions are supplied at a higher flow rate, then thegelification may occur at a faster rate. If the concentrated solutionsare supplied at a lower flow rate, then the gelification may occur at aslower rate.

One example of a multi-composition obturation material may be formed bya trigger comprising an ionic reaction between two or more materials. Insuch arrangements, an obturation base material can be reacted or mixedwith a gelifying initiator or agent. For example, sodium alginate (aflowable base material) may be in a liquid form when dissolved in waterwith a very low level of cations, but can gelify substantiallyinstantaneously when in the presence of a gelifying initiator (e.g.,calcium ions, potassium ions, etc.). When in a flowable state, thesodium alginate can be delivered into the treatment region of the tooth(e.g., the tooth chamber, root canal spaces, carious region, etc.) byway of the disclosed handpieces (FIG. 4A-8B), or by any other suitabledelivery devices. The sodium alginate solution can gelify upon exposureto calcium or calcium containing compounds.

In some embodiments, the sodium alginate and calcium-containing compoundcan be delivered separately and can be mixed in the treatment region ofthe tooth. For example, in such embodiments, one outlet of the handpiececan deliver the sodium alginate to the tooth, and another outlet candeliver the calcium-containing compound to the tooth. The sodiumalginate and calcium ions can react in the treatment region of thetooth. In other embodiments, the sodium alginate and calcium-containingcompound can be mixed and reacted in the handpiece just prior to beingdelivered to the tooth. For example, the calcium-containing ions may becombined with the sodium alginate in a reservoir just prior to exitingthe handpiece, such that the composition remains flowable. In yet otherembodiments, coated calcium particles can be provided within theflowable sodium alginate solution. An encapsulant that coats the calciumparticles can be broken or dissolved to release calcium when agitated,for example, by acoustic or shear forces that can be imparted on theparticles by a pressure wave generator or other source. Although sodiumalginate is one example of a base obturation material, any othersuitable base material can be used, such as agar, collagen, hyaluronicacid, chondroitin sulfate, ulvan, chitosan, collagen/chitosan,chitin/hydroxyapatite, dextran-hydroxyethyl methacrylate, and/orpluronic. Furthermore, a radiopaque material may also be mixed with theobturation material to assist with radiographic visualization ofobturation or filling for reimbursement (insurance) and assessmentpurposes.

In some embodiments, the ionic solution or gelifying initiator may bedispensed by way of a syringe and needle. In other embodiments, theionic solution may be dispensed by a handpiece including a pressure wavegenerator, such as that disclosed herein. In one embodiment, the ionicsolution or gelifying initiator may be dispensed by saturated cottonpositioned in the pulp chamber of the tooth. As disclosed herein, insome arrangements, calcium compounds may be introduced into the polymersolution and trigger gelification. The solubility of the particularcalcium compound may be used to control the time required for the gel toform. As an example, calcium chloride can initiate immediate gelformation due to its high water solubility, whereas the use of calciumsulfate or calcium carbonate can delay gel formation because of theirlower solubility in water. In various embodiments, gelification may beachieved by ions that may be naturally provided by the surroundingdentin. Ions can diffuse from the dentin into the polymer solution(e.g., sodium alginate) and trigger gelification.

In some embodiments, ions (e.g., calcium) may be provided by commondental compounds such as dental sealers, calcium hydroxide or mineraltrioxide aggregate (MTA). The dental compound may be applied anywhere inthe proximity of the solution, for example, at the top of the canal andcan initiate gelification by diffusion. Calcium rich compounds may alsobe introduced into the canals as points (e.g., calcium hydroxidepoints).

In some embodiments, the gelifying initiator (e.g., ions) may beencapsulated in nano/microspheres that are dispersed in the polymersolution. When subjected to high shear or oscillation, or any otherchemical or physical phenomena, the encapsulating shell may be torn andions can be released into the polymer solution within the root canalsystem or other treatment region. Such release can induce gelificationof the polymer solution within the root canal. As explained above, insome arrangements, activation of the pressure wave generator can causethe encapsulating shell or encapsulant to break apart, which can controlthe gelification of the polymer solution. In some embodiments,ion-enriched microspheres or particles that are not subject to shear orthat are shear resistant may be dispersed into solution within the rootcanal system. Once full obturation is achieved (e.g., assisted by thepressure wave generator in some embodiments), the particles ormicrospheres can slowly dissolve into solution, thereby initiatinggelification. In some embodiments, light or heat can be applied to theencapsulated initiator to cause the release of the initiator.

In various embodiments, ions (e.g. calcium) may be introduced intosolution by flowing the polymer solution (e.g. sodium alginate) throughan ion (e.g. calcium) enriched capillary tube (e.g. guide tube orneedle). By flowing through the tube, ions are introduced into solutionand thereby can initiate gelification.

Further, when using sodium alginate as a base material for gelformation, various types of ions may be used. For example, cross-linkingof the polymers can be achieved using divalent ions. Divalent ions thatmay be used as a gelifying initiator may include Ca²⁺, Ba²⁺, Sr²⁺, Mg²⁺,and/or Fe²⁺. In some embodiments, barium (Ba²⁺), may be used under itsbarium sulfate form as a gelifying agent or initiator. Advantageously,barium sulfate is also a radiopaque compound, such that barium sulfatemay serve as a dual purpose compound, allowing for full gelification aswell as radiopaque control of the proper extent of obturation.

In some embodiments, instead of using sodium alginate as a baseobturation material, Kappa-Carrageenan can be used in conjunction withan initiator that includes potassium ions. In other embodiments,Iota-Carrageenan can be used in conjunction with an initiator thatincludes calcium ions. In some embodiments, the polymer base materialmay be a poly(carboxylate) polymer. For example, the polymer basematerial may include poly(acrylic acid), poly(methacrylic acid),copolymers of acrylic and itaconic acid, copolymers of acrylic andmaleic acid, or combinations thereof. These polymers can be cross-linkedthrough reaction with di- or trivalent cations, such as Ca²⁺, Zn²⁺,and/or Al²⁺.

In various embodiments, crosslinking may be achieved through aglass-ionomer reaction, e.g., an acid-base reaction between apoly(carboxylic acid) and a reactive, ion-leachable glass in thepresence of water. The reactive, ion-leachable glasses may comprise afluoroaluminosilcate glass. The reactive fluoroaluminosilcate glass mayfurther comprise calcium, barium, or strontium ions, and may furthercomprise phosphates and/or borates. In various embodiments, the polymercan be gelified via a reduction-oxidation reaction (redox) when in thepresence of ions. It should be appreciated that, while the examplesabove discuss the use of hydrogels, the examples are non-limiting andthe same concepts may apply to organogels.

In various embodiments disclosed herein, the gel can comprise a polymermatrix that traps fluid within its structure. For example, in the caseof a hydrogel, this trapped fluid is water. The physical mechanicalproperties of the matrix may be controlled based on, for example,concentration of polymer or molecular properties (e.g. High M or High Ggrade in the case of sodium alginate). The matrix formed after gelformation (e.g. cross-linking) may exhibit various physical propertiessuch as, for example, viscosity, strength, elasticity or even “mesh”size. The physical properties of the gel matrix may be tailored by wayof the gel formation process. For example, in one embodiment, thephysical properties of the obturation material may be controlled bygeneration of a gel using cross-linking. In various arrangements, thephysical properties may be controlled by generation of a gel usingthermally sensitive polymer molecules. In one embodiment, the physicalproperties may be controlled by generation of a gel using polymermolecules with free radicals, e.g., free radical polymerization.

In some embodiments, the physical properties of the obturation materialmay be controlled by combining more than one polymer (e.g. two polymersA & B). The molecules of polymer A may be linked to molecules of polymerB. For example, each polymer B molecule may be linked to polymer Amolecules such that a matrix A-B-A-B . . . is formed. The link may becovalent or ionic in various embodiments. Click chemistry may be used tocontrol this process in some arrangements. In some embodiments, polymerA may be selected from epoxy prepolymers, while polymer B may selectedfrom amine prepolymers. The epoxy prepolymer can comprise at least tworeactive epoxy (oxirane) functional groups and may be selected frombis(glycidyl ether) of bisphenol-type oligomers, bis(glycidyl ether) ofpoly(alkylene glycol) oligomers, triglycidyl ether oftrimethylolpropane, triglycidyl ether of ethoxylatedtrimethylolpropoane, poly(glycidyl ether) of pentaerythritol, and thelike. The amine prepolymer may comprise bis(aminoalkyl) poly(alkyleneglycol), ethylenediamine, diethylenetriamine, triethylenetetramine,poly(ethylene imine), and the like. In other embodiments, polymer A maycomprise a poly(isocyanate) and polymer B may comprise a polyol. Inother embodiments, different types of polymers may be formed. Forexample, the compound may include copolymers that are randomlydistributed. In some embodiments, block copolymers may be used. Invarious arrangements, polymerization and cross-linking can happen at thesame time.

The polymer matrix may also be formed because of thermo-sensitivity ofthe molecule, in various arrangements. The physical mechanicalproperties of a gel (e.g. “mesh” size) may be adjusted to control theresistance of a gel to different chemical components, compounds ororganisms. For example, the physical mechanical properties of a gel(e.g. “mesh” size) may be adjusted to trap organisms (e.g. bacteria) andprevent their proliferation after obturation. Trapping of bacteria mayinduce starvation or desiccation of the micro-organisms, which mayinduce death of the micro-organism. In some embodiments, the physicalmechanical properties of a gel (e.g. “mesh” size) may be adjusted bycontrolling the concentration of the gel. In some embodiment, thephysical mechanical properties of a gel (e.g. “mesh” size) may beadjusted by controlling the molecular weight of the gel. In variousembodiments, the physical mechanical properties of a gel (e.g. “mesh”size) may be adjusted by using different grades of polymers (e.g.different shapes) that induce different gelification patterns (e.g.different cross-linking pattern).

The obturation material may also comprise a gel that possesses variousdegradation properties that may be tailored to the application andexpected life-time required of the obturation material. For example, insome cases, degradation of the obturation material may occur by surfaceerosion or bulk erosion. The rate of degradation may be controlled byadjusting the degree of oxidation of the polymer, by changing the purityof the polymer, and/or by adjusting the chain length or density of thepolymer. In some embodiments, the degradation properties of theobturation material may be adjusted by changing the fluid used in theformation of the gel (e.g. fluid trapped in the structure).

In various embodiments, light may trigger, or assist in triggering, thegelification reactions described herein. For example, in someembodiments, photo-induced gelification may be used. Photo-inducedgelification may be achieved using ultraviolet (UV) light or visiblelight in various arrangements, typically in the presence of aphotoinitiator. In some embodiments, gels such as pluronic basedhydrogels (e.g. DA Pluronic F-127) may be formed when exposed with UVand/or visible light. Such polymer solutions may be introduced in theroot canal system or other suitable treatment regions. Once introducedinto the root canals or treatment region, a UV and/or visible lightsource may be introduced on the coronal portion of the tooth or into thepulp chamber to initiate gelification. The UV and/or visible lightsource may be provided by a dental curing light. The source may also belocated on the treatment handpiece 3 (e.g., near the proximal end of theguide tube) and may be activated after delivering the light-curablepolymer solution.

In some embodiments, gels such as Dex-HEMA (Dextran-hydroxyethylmethacrylate) based gels may be initiated by visible light. Lighttriggers can be achieved by delivering visible light to the coronalportion of the tooth or in the pulp chamber. The visible light sourcemay be a regular light source or a visible dental curing light (e.g.blue). The visible light source may be located on the treatmenthandpiece 3 (e.g., near the proximal end of the guide tube) andactivated after delivery of the polymer solution.

Additional examples of photo-inducible gels may include systems based onpoly(alkylene glycol) diacrylate, poly(alkylene glycol) dimethacrylate,trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropanetri(meth)acrylate, pentaerythritol poly(meth)acrylate, and the like, aswell as combinations thereof, preferably in the presence of aphotoinitiator.

Another gelification trigger that may be used in accordance with variousembodiments is heat. Some hydrogels (e.g., agar) may gelify at knowntemperatures. Some of these materials may, however, exhibit a hysteresisbehavior that may be useful in the obturation process. Such athermally-activated gel can be heated to a melting temperature T1 toreach a liquid state. After reaching the liquid state, the solution cancool down and transition back to a gel structure at a temperature T2.The gelification temperature T2 can be much lower than the meltingtemperature T1. As an example, agar gels may exhibit this hysteresisproperty. For example, a 1.5% w/w agar gel melts at about 85° C. butgelifies at a temperature T2 between about 32° C. and about 45° C. Thehysteresis properties of agar may be tailored to the obturation process.For example, a hydrogel such as agar (in liquid form) may be heated anddelivered to the root canal system at a temperature larger than T2 suchthat the hydrogel is in a flowable state sufficient to flow through thetreatment region. Heat may be delivered to the obturation materialdirectly by conduction or radiation, or indirectly by, for example, heatabsorbing elements inside the material, such as nanoparticles thatabsorb a specific wavelength of light and produce heat inside thematerial. As the gel cools down (e.g., if the body temperature is belowT2), the solution may gelify within the root canal system or treatmentregion. Heat may also catalyze a polymerization or curing process invarious embodiments.

4. Resin-Based Obturation Materials

In some embodiments, the obturation material may be selected fromcurable (e.g., hardenable) resin-based materials. The resin-basedmaterial may be delivered into the tooth in its uncured, flowable stateand may be cured following delivery using a trigger. The trigger may bean external stimulus and may include radiation, e.g. actinic radiation.The trigger may also be thermal energy or mechanical energy, e.g. sonicand/or ultrasonic energy (which may be provided by the pressure wavegenerator). The trigger may further comprise a chemical reaction,including, but not limited to, a redox reaction to initiatepolymerization, e.g., free radical polymerization of ethylenicallyunsaturated monomers (e.g. acrylate, methacrylate). Chemical triggersmay further comprise nucleophiles to initiate anionic polymerization(e.g. cyanoacrylate) and further may comprise acids to initiate cationic(ring-opening) polymerization. Curing may also be achieved throughaddition polymerization of complementary resin monomers having at leasttwo reactive functional groups. Examples for complementary resinmonomers include epoxy-amine systems, epoxy-thiol systems,isocyanate-alcohol (urethane) and isocyanate-amine (polyurea) systems.

In some embodiments, the resin-based obturation material may bedelivered by way of a syringe, or any dental or non-dental materialdelivery device. For example, as explained above, the resin-basedobturation material may be delivered using the pressure wave generator 5disclosed herein. In various embodiments, the resin-based material maybe unfilled or may include a particulate filler. Fillers may be used toadjust viscosity and rheological properties of the obturation material.In some arrangements, the filler may also impart radiopacity forverification during or after the obturation procedure. Examples forradiopaque fillers include without limitation barium sulfate, bismuthoxychloride, bismuth subcarbonate, ytterbium fluoride, yttrium fluoride,and the like. Particulate fillers may also be used to advantageouslyreduce polymerization shrinkage during curing.

In various embodiments, the resin-based material includes monomershaving at least one ethylenically unsaturated group. Examples ofethylenically unsaturated groups include vinyl groups, acrylate and/ormethacrylate groups. Some resin monomers may comprise at least twoethylenically unsaturated groups. Examples of monomers containing twoethylenically unsaturated groups may include without limitationdi(meth)acrylate monomers selected from bisphenol-A diglycidyldimethacrylate (BisGMA), ethoxylated bisphenol-A dimethacrylate(EBPADMA), triethyleneglycol dimethacrylate (TEGDMA), urethanedimethacrylate (UDMA), and other suitable monomers.

The resin-based material may further include adhesion promoters toincrease adhesion of the material to the tooth structure to provide amore efficient seal with the tooth. Adhesion promoters may containacidic groups including without limitation carboxylic, phosphoric,phosphonic, sulfonic, and sulfinic groups. The adhesion promoter mayfurther be capable of copolymerizing with the other resin components. Insome embodiments, the resin-based obturation material may include aphotoinitiator system that may be cured after being delivered into thetooth using actinic radiation, e.g. UV and/or visible light. The lightsource may be a standard dental curing light unit.

In some embodiments, the resin-based material may comprise twocomponents, termed a base material and catalyst, respectively. Theresin-based obturation material may be cured chemically through a redoxreaction. The catalyst part may include oxidizing species includingwithout limitation peroxides, e.g. organic peroxides. The organicperoxide may be selected from benzoyl peroxide, tert.-butylhydroperoxide, cumene hydroperoxide, and the like. The base material mayalso comprise reducing co-initiators. Reducing co-initiators may includeamines, e.g. teriary alkyl and/or aryl amines, thiourea, and the like.The two-part resin-based material may further contain a photoinitiator,as explained above.

5. Moisture Cure Systems

In some embodiment, the obturation material may be hardened by reactingwith water or other residual moisture inside the root canal system ortreatment region. The water may act as catalyst to initiate thehardening reaction, or the water may be a reactant in stoichiometric ornear stoichiometric relative amounts. In some embodiments, the moisturecurable material may comprise cyanoacrylate esters of the generalformula CH2═C(CN)COOR, where R is a linear or branched alkyl radical,aryl radical, or combinations thereof. The ester group R may furthercomprise heteroatoms such as oxygen, nitrogen, phosphorus, and sulfuratoms, and combinations thereof. Non-limiting examples of suitable alkylcyanoacrylates include methyl cyanoacrylate, ethyl cyanoacrylate, butylcyanoacrylate, branched or linear octyl cyanoacrylate, and the like. Incertain embodiments, additives such as plasticizers, inert fillers, andstabilizers may be added. In some embodiments, a radio contrast agentmay further be present. Without being bound by theory, the chemicalstructure of the ester group R may be utilized to adjust the rate of thehardening reaction. It is believed that bulkier R groups provide lowerreaction rates, which may increase the setting time. It is furtherbelieved that more hydrophilic R groups may facilitate penetration ofthe uncured liquid into small spaces within the root canal system.

In various embodiments, the moisture curable material may comprisecondensation cure silicone. Suitable examples include one-partcondensation cure systems, commonly referred to as one-part roomtemperature vulcanizeable (RTV) silicones. Suitable silicone materialsmay be selected from silicone prepolymers functionalized with readilyhydrolysable groups including without limitation acetoxy (O(CO)CH3),enoxy (O(C═CH2)CH3), alkoxy (OR; R is an alkyl radical), and oxime(ON═CR1R2; R1, R2 are identical or different alkyl radicals).Optionally, silanol functionalized silicone prepolymers may further bepresent. Without being bound by theory, exposure to moisture may lead tohydrolysis of these hydrolysable groups followed by rapid crosslinking.In certain embodiments, the material may further contain radio contrastagents.

In some embodiments, the moisture curable material may be selected frommineral cements. For the purposes of the present disclosure, the termmineral cement includes siliceous, aluminous, aluminosiliceous materialsin the presence of calcium species such as calcium oxide, calciumhydroxide, calcium phosphate, and others. These cements may hardenthrough hydration and crystallization of the hydrated species.Non-limiting examples include Portland cement, mineral trioxideaggregate (MTA), calcium aluminate, calcium silicate, and calciumaluminosilicate. In some embodiments, the mineral cement may be providedas a dispersion of the solid cement particles in a non-reactive, watermiscible liquid. In some embodiments, additives including radio contrastagents may be present. Optionally, organic modifiers including polymericmodifiers may further be present.

6. Precipitation or Evaporation Hardening Systems

In some embodiments, the obturation material may harden throughprecipitation. The obturation material can comprise a polymer dissolvedin a first solvent. The first solvent can be any suitable material, suchas a solvent in which the polymer is substantially soluble or miscible.Hardening of the material can be caused by combining the polymersolution with a second solvent or liquid that is miscible with the firstsolvent but that does not display appreciable solubility for thepolymer, which causes the polymer to precipitate out of solution.Advantageously, the second solvent can comprise water and the firstsolvent can comprise a water miscible solvent for the polymer. Examplesfor water miscible solvents include, without limitation, alcohols suchas ethanol, iso-propanol, and the like, acetone, dimethyl sulfoxide, anddimethyl formamide. Examples of suitable water-insoluble polymersinclude without limitation partially hydrolyzed poly(vinyl acetate) andcopolymers of vinyl alcohol, vinyl pyrrolidone, or acrylic acidcopolymerized with hydrophobic vinyl monomers such as ethylene,propylene, styrene, and the like.

In another embodiment, the obturation material may harden throughevaporation. The obturation material may comprise a solution of apolymer in a volatile solvent. After delivery of the material into thetooth, the volatile solvent can be evaporated, leaving behind a solidpolymer. Evaporation of the solvent may proceed spontaneously or it maybe assisted by any suitable mechanism, such as heating or reducedpressure (e.g., vacuum).

7. Catalytic Cure Systems

In some embodiments, the setting or curing reaction may be induced byadding a suitable catalyst to a catalytically curable compositionimmediately prior to, during, or immediately following delivery of saidcomposition into the root canal system or treatment region. Appropriatedistribution of the catalyst throughout the curable composition may beprovided through diffusion or it may be provided through agitation. Asexplained herein, agitation may advantageously be provided by thepressure wave generator 5 and systems disclosed herein.

In various embodiments, the catalytically curable material can comprisea curable resin mixture. The curable resin mixture may be selected fromethylenically unsaturated monomers. In various embodiments, theethylenically uinsaturated monomers may be selected from (meth)acrylatemonomers including acrylate, methacrylate, diacrylate, dimethacrylate,monomers with three or more acrylate or methacrylate functional groups,and combinations thereof. The (meth)acrylate monomers may advantageouslybe hydrophilic to facilitate penetration of the filling material intosmall spaces within the root canal system; however, the (meth)acrylatemonomers may also be hydrophobic in other arrangements. Examples forparticularly suitable (meth)acrylate monomers include withoutlimitation, methyl methacrylate, hydroxyethyl methacrylate,hydroxypropyl methacrylate, hydroxyethoxyethyl methacrylate,poly(ethylene glycol) methacrylate, ethylene glycol dimethacrylate,diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,poly(ethylene glycol) dimethacrylate, hexanediiol dimethacrylate,urethane dimethacrylate, bisphenol-A diglycidyl dimethacrylate (BisGMA),ethoxylated bisphenol-A dimethacrylate, trimethylolpropanetrimethacrylate, pentaerythritol tetramethacrylate, ethoxylatedtrimetgylolpropane trimethacrylate, and their acrylate analogues. The(meth)acrylate monomers may be radically polymerizable. Free radicalpolymerization may be caused by any suitable catalyst system orcombination, including without limitation thermal and redox free radicalinitiator systems. Examples for thermal free radical initiators includeperoxide salts, hydrogen peroxide, and organically substituted peroxidesand hydroperoxides, as well as azo compounds. Non-limiting examples forredox free radical initiator systems include peroxide-aminecombinations, peroxide-thiourea combinations, peroxide-sulfinic acidcombinations, peroxide-ferrous salt combinations, peroxide-cuprous saltcombinations, and combinations thereof. One component of the redoxinitiator system may be part of the liquid catalytically curablecomposition, and the second component may be added immediately prior to,during, or immediately following delivery.

In some embodiments, radio contrast agents may further be added to thematerial. The radio contrast agent can advantageously comprisesnanoparticles having a mean particle size of less than about 200 nm.Advantageously, the nanoparticles can be substantially non-agglomerated.Suitable nanoparticles may be selected from heavy metal, heavy metalsalt, and heavy metal oxide nanoparticles. Examples include withoutlimitation colloidal, silver, gold, platinum, palladium, and tantalumparticles, zirconia, yttria, ytterbia, yttrium fluoride, ytterbiumfluoride, tungstate, and bismuth oxide particles. In another embodiment,the composition may further contain polymerization mediators includingchain-transfer agents, stabilizers, accelerators, and the like. Thecomposition may further comprise rheology modifiers and colorants. Inyet another embodiment, the composition may further comprise aphotoinitiator system to provide additional light-cure capabilities,thus allowing the practitioner to rapidly seal the coronal aspect of theroot canal system.

8. Light Cure Systems

In various embodiments, the setting or curing reaction for theobturation material may be induced by exposing a photo-curablecomposition to actinic radiation, such as ultraviolet and/or visiblelight. The obturation material may be delivered into the root canalsystem through the pressure wave generators and systems disclosedherein, and at least part of the material can be exposed to a source ofactinic radiation. Exposure may be direct or indirect by irradiating thematerial through at least part of the tooth structure.

In some embodiments, the obturation material may be substantiallytranslucent and may further display a refractive index higher than therefractive index of the tooth structure. Without being bound by theory,in such embodiments, the high refractive index material may act as awaveguide material transmitting actinic radiation through internalreflection throughout at least part of the tooth's internal volume. Thephoto-curable composition may be selected from ethylenically unsaturatedmonomers with or without the presence of a separate photoinitiator.Examples of suitable ethylenically unsaturated monomers include withoutlimitation (meth)acrylate monomers as described herein. Advantageously,at least part of the monomer composition may comprise high refractiveindex monomers or additives. The refractive index can be greater thanabout 1.5, preferably greater than about 1.6. Non-limiting examples of asuitable (meth)acrylic high index monomer include halogen-substituted(meth)acrylates, zirconium (meth)acrylates, hafnium (meth)acrylates,thio-substituted (meth)acrylates such as phenylthiolethyl acrylate andbis(methacryloylthiophenyl)sulfide, and combinations thereof.Optionally, high refractive index nanoparticles having a mean particlesize of less than about 200 nm may further be added. Advantageously, thehigh refractive index nanoparticles can be substantiallynon-agglomerated. Non-limiting examples of suitable nanoparticlesinclude zirconia and titania colloidal particles; other high refractiveindex materials may also be suitable. In some embodiments, thephotoinitiator system may be selected from type I or type IIphotoinitiator systems or a combination thereof. Non-limiting examplesof type I initiators may include benzoin ethers, benzyl ketals,α-dialkoxy acetophenones, α-hydroxy alkylphenones, α-aminoalkylphenones, and acyl phosphine oxides; examples of type II initiatorsinclude benzophenone-amine combinations, thioxanthone-aminecombinations, α-diketone-amine combinations such as phenylpropanedione-amine and camphorquinone-amine systems, and combinationsthereof.

9. Further Examples of Obturation Materials and Combinations

Additional examples of obturation materials are disclosed in Table 1below. It should be appreciated that the disclosed materials areexamples; other suitable combinations of materials and cures may besuitable.

TABLE 1 Cure Type Chemistry Description Example Benefits Two Epoxy-amineComponent A: good long term component hydrophilic stability chemicaldiepoxy hydrophilic nature cure prepolymer (e.g. may facilitatePEG-diglycidyl tubule ether) + penetration poly(glycidyl) slightexpansion by crosslinker) water absorption Component B: possible tohydrophilic improve seal polyamine (e.g. PEG diamine) dispersed radiocontrast agent Two Alginate + Component A: good component Ca²⁺ sodiumalginate biocompatibility chemical solution in water excess Ca may cureComponent B: provide calcium salt remineralization solution propertiesComponent B can also include Ba or Sr salt for radiopacity Two metaloxide - Component A: good component polyacid acid-dissolvablebiocompatibility chemical (polyalkenoate metal oxide (e.g.remineralizing cure or glass HAp, CaO, ZnO, may be ionomer reactiveglass) possible cement) Component B: hydrophilic polyacid, e.g. fortubule poly(acrylic penetration acid) Light curable resin can be addedfor rapid coronal seal. dispersed radio contrast agent Two VPS additionComponent A: excellent component silicone vinyl long term chemicalpoly(siloxane) + stability cure Pt catalyst good Component B:biocompatibility Hydrosilane crosslinker dispersed radio contrast agent(similar to “Gutta Flow” matrix without dispersed gutta perchaparticles) One Cyanoacrylate Water inside root No additional component(CA) canal catalyzes catalyst moisture cure setting reaction; neededhydrophobic/ good tubule hydrophilic penetration may balance can be bepossible adjusted (within limits) One Condensation silanol- Noadditional component cure silicone terminated catalyst moisture cure(one-part siloxane needed RTV silicone) prepolymer + good hydrolysis-biocompatibility sensitive good long term crosslinker stabilitydispersed radio contrast agent One Refractory calcium silicates,excellent component cement aluminosilicates + long term moisture cureradiopaque stability metal oxide, excellent water misciblebiocompatibility carrier liquid; good dimensional MTA and “bio-stability ceramics” are bonds to dentin similar. Precipitation DissolvedContact with Non-reactive or polymers in water inside the systemsevaporation water root canal or Solvent may hardening miscible orevaporation of facilitate highly volatile volatile solvent tubulesolvents causes polymer penetration to precipitate Catalytic VPSaddition Single part vinyl excellent cure silicone siloxane + long termhydrosilane, stability dispersed radio good contrast agent;biocompatibility Pt catalyst delivered into tooth; solvent may be usedto control viscosity Catalytic Acrylic/ PEG excellent cure methacrylic(meth)acrylates, long term resin PEG stability di(meth)acrylates, gooddispersed biocompatibility radio contrast tunable agent hydrophilicityperoxide catalyst to facilitate delivered by tubule syringe; penetrationadditional light slight expansion cure possible to possible throughprovide rapid water sorption to coronal seal compensate for shrinkageLight cure Acrylic/ (meth)acrylate - excellent methacrylic PEG systemwith long term resin high refractive stability index (RI) good additives(e.g. biocompatibility zirconia tunable nanoparticles) hydrophilicityhigh RI additive to facilitate may be sufficient tubule to providepenetration radiopacity; slight expansion RI higher than possiblethrough that of dentin water (~1.6) may allow sorption to the materialto compensate act as wave for shrinkage guide to ensure complete cure

B. Obturation Material Removal

In some embodiments, it can be desirable to remove an obturationmaterial that fills a treatment region of the tooth. For example, theclinician may desire to remove the obturation material in order tore-treat the treatment region if the treatment region becomes infectedor if the obturation or restoration material is damaged. In someembodiments, the hardened obturation material may be removed using thepressure wave generator 5 disclosed herein. As one example, a fullygelified hydrogel (e.g., a calcium-alginate gel) may be broken downusing a treatment handpiece 3 that includes a pressure wave generator 5.A suitable treatment fluid can be supplied to the obturated region ofthe tooth (e.g., an obturated root canal). The pressure wave generator 5(which may comprise a liquid jet device) can be activated to propagatepressure waves through the treatment fluid to dissolve the obturationmaterial. As explained herein, the pressure wave generator may also beused to supply the treatment fluid to the obturated region. The pressurewaves propagating through the obturation material can assist inagitating, breaking apart, and/or dissolving the obturation material. Inother embodiments, the obturation material can be removed via heat,mechanical contact, light, electromagnetic energy, rinsing, suction,etc.

Any suitable treatment fluid may be employed to remove the gelifiedobturation material. For example the treatment fluid used to remove theobturation material may comprise a solvent specific to the obturationmaterial of interest. In one embodiment, ionically cross-linkedhydrogels, such as calcium-alginate gels, may be broken down using asolution of sodium hypochlorite or chelating agents (e.g., EDTA, citricacid, stearic acid). For example, chelating agents may help to breakdown gels (e.g. ionically cross-linked hydrogels) by breaking the ioniclinks between molecules, which may be formed using divalent ions. Forcalcium-based gels, EDTA may be used based on its calcium bindingproperties. Thus, in some embodiments, EDTA or other treatment fluid maybe supplied to the obturated region, and the pressure wave generator 5can be activated to assist with removing the calcium-based gel.

In various embodiments, two different treatment fluids may be used whenremoving the obturation material. One treatment fluid may be configuredto quickly diffuse within the obturation medium, and the other treatmentfluid can be configured to break down the structure of the obturationmaterial matrix. For example, sodium hypochlorite can be used incombination with EDTA.

C. Other Characteristics of Obturation Materials

The obturation materials disclosed herein can include a flowable stateand a cured or hardened state. When in the flowable state, theobturation material can be delivered to the treatment region (e.g., rootcanal). For example the material can be flowable such that it can bedelivered into root canals, including into all of the isthmuses andramifications. The flowability or viscosity of the material may dependat least in part on the method of delivery and agitation that wouldassist in filling complex and small spaces inside the tooth and rootcanal system. For example, if the material is delivered by syringe, theobturation material may be less viscous (e.g., more flowable) so that itcan penetrate into small spaces (e.g., micron size spaces) without usingexcessive force that could potentially cause extrusion of materials intothe periapical space and potentially harm the patient. Accordingly, aflowable obturation material can advantageously fill small spaces whileprotecting the patient from injury. In other arrangements, the viscosityof the obturation material can be selected such that the obturationmaterial can form a liquid jet when it passes through a nozzle ororifice. For example, an obturation material used to form a liquid jetmay have a viscosity similar to that of water or other treatment fluids(such as EDTA, bleach, etc.). The flowable obturation material can behardened or cured after it fills the treatment region in order toprovide a long-term solution for the patient.

For gel-based materials, an obturation gel in its flowable state (e.g.,before gelification) can be efficiently delivered into the root canalsystem based at least in part on its relatively low viscosity. The gelmay be degassed in some arrangements, e.g., substantially free ofdissolved gases. In some embodiments, the viscosity of the obturationmaterial may be controlled by adjusting the polymer concentration or themolecular weight of the molecule. In other embodiments, the viscosity ofthe gel-based obturation material may be controlled by exposing thepolymer molecules to specific shear/strain rates. The molecules may bedesigned and formed in such a way that when the molecules are subjectedto high deformation rates, the molecules or chemical links may break andtherefore induce a lower apparent viscosity. In some embodiments, themolecules may go back to their original state (repair) when the sourceof deformation is removed, therefore regaining the higher viscosity.

In various embodiments, the obturation material may be delivered by wayof a syringe or any dental or non-dental material delivery device. Insome embodiments, the obturation material can be delivered by thehandpiece 3 disclosed herein. For example, the pressure wave generator 5can be used to deliver the obturation material (or various components ofthe obturation material). When delivered by the pressure wave generator5, the solution can be passed through a small orifice by way of thehandpiece 3. A stream of obturation material can be created, and theobturation material can be delivered within the root canal system (orother treatment region). The resulting flow of obturation material intothe root canal system, the broadband frequency pressure waves, or acombination of both, helps to ensure a complete obturation of the rootcanal system (or treatment region). Thus, in some embodiments, apressure wave generator 5 (such as a liquid jet device) can be activatedbefore or during obturation to enhance the obturation of the root canalsystem. The liquid stream of obturation material may be a high velocitystream, and may pass through fluid that is retained at the treatmentregion. The stream of obturation fluid may be diverted to ensureefficient and safe delivery of material. The obturation material may ormay not be degassed, e.g., substantially free of dissolved gases.

The viscosity (flowability) of the material may remain substantiallyconstant or it may vary during the procedure. For example, during thedelivery of the material into the tooth, the viscosity may be low, butthe viscosity may increase after the filling is completed. The viscositycan be increased during the procedure to stabilize the obturationmaterial in place after completion of the filling procedure. At or nearthe beginning of the procedure, a flowable liquid obturation materialcan be used, which can be cured into a semi-solid or solid obturationmaterial after filling is completed.

The viscosity of the material may change automatically or by way of anexternal trigger or force. The viscosity of the obturation material maychange by way of changes in chemical reaction in the material ormolecular structure of the material. The external trigger or force maycomprise an external stimulus including energy having one or morefrequencies, or ranges of frequencies, e.g., in the electromagnetic wavespectrum. For example, in some embodiments, the external trigger mayinclude energy having frequencies or ranges of frequencies atfrequencies corresponding to microwaves, UV light, visible light, IRlight, sound, audible or non-audible acoustics, RF waves, gamma rays,etc. The trigger may comprise an electrical current safe for a human ormammalian body, a magnetic field, or a mechanical shock. In someembodiments, a clinician or user can engage the external trigger tochange the obturation material from a substantially flowable state(e.g., a liquid-like state in some arrangements) to a substantiallysolid or semi-solid state. For example, when the filling is complete oralmost complete, the clinician or user can activate the trigger toconvert or change the obturation material to a solid or semi-solidstate. In still other embodiments, the obturation material may beconfigured to cure (set) automatically. The setting and curing may beirreversible and permanent, or the setting and curing may be reversiblesuch that the obturation material can be more easily removed.

In some embodiments, the obturation material may be seeded with anothermaterial which can preferentially absorb a specific type ofelectromagnetic wave or a plurality of electromagnetic waves (orfrequencies thereof). For example, near-IR absorbing gold nanoparticles(including gold nanoshells and nanorods) may be used to produce heatwhen excited by light at wavelengths from about 700 to about 800 nm. Insuch embodiments, heat may help in reducing the viscosity of thematerial, rendering it more flowable until the material is delivered andhas filled substantially all the spaces inside the tooth and rootcanals. The material viscosity can then return to its original state asthe heat is dissipate.

In another embodiment, the filling material may be seeded by particlesof a magnetic material, such as stainless steel. In such an embodiment,the magnetic material may be driven into the root canals and smallspaces remotely by way of an external magnet. In another embodiment, theobturation material may be seeded with electrically conductive particleswhich can help in controlling the delivery of the material. For example,when the obturation material reaches the apex of the root canal, thecircuit electrical circuit is completed and the console may signal theoperator that the filling process is completed. In yet otherembodiments, the obturation material can be made electrically conductiveand, through safe electrical currents that are absorbed by the energyabsorbing material, heat can be generated. The heat can act to reducethe viscosity of the filling material, rendering it more flowable untilthe source of energy is stopped and the heat is dissipated. The materialcan then become more viscous as it cools down until it hardens, forexample, as a semi-solid or solid material.

In various arrangements, the obturation material may have a surfacetension that is sufficiently low such that the material can flow intosmall complex (or irregular) spaces inside the tooth. Having a lowsurface tension can reduce or eliminate air bubbles trapped in thespaces of the canals or tooth. In some embodiments, the obturationmaterial can be radiopaque. Radiopaque obturation materials can allowthe clinician to monitor the location and quality of obturation materialinside the tooth. Radiopaque obturation materials may also be used toalert the doctor or clinician in the future about which teeth havereceived root canal treatment(s) in the past.

The obturation material may comprise a biocompatible material configuredto minimize or reduce any negative effects that the filling orobturation material may have on the body. For example, the obturationmaterial can be designed to prevent the growth of bacteria, biofilms,parasites, viruses, microbes, spores, pyrogens, fungi or anymicroorganisms that may trigger patient/body reactions orinfections/diseases. For example, the growth of bacteria or biofilms maybe prevented or reduced by way of an antibacterial agent that isdesigned such that it kills bacteria while not inducing bacterialresistance to such agent. The antibacterial agent may be suitable for invivo use and can be configured such that it does not induce unwantedbody/patient reactions. The antibacterial agent may also be designedsuch that it does not react with the various components of theobturation material. In some embodiments, the antibacterial agent may bedesigned such that it is soluble or miscible in the obturation material.The antibacterial agent may be combined with other agents (e.g.surfactants, polymers, etc.) to increase its potency and efficiency. Insome embodiments, the antibacterial agent can be encapsulated in acoating. In some arrangements, the antibacterial agent may be replacedor supplemented by antiparasitic agents, antiviral agents, antimicrobialagents, antifungal agents or any agents that may prevent development ofinfections/diseases or patient/body reactions.

Moreover, the obturation material may be configured to be naturallyabsorbed by the body over time. The absorption of the obturationmaterial may occur in combination with pulp tissue regeneration thathelps the pulp tissue to grow and fill the root canal space as thefilling material is absorbed. In some cases, the obturation material maybe absorbed without any pulp tissue regeneration. In some cases, theobturation material may not be absorbed by the patient's body. Theobturation materials disclosed herein can also be configured to bondsecurely to dentin. Bonding to dentin can help provide a better seal,which can then reduce the rate and extent of penetration of contaminantsand bacteria.

Some obturation materials disclosed herein (e.g. long chain polymers orcross-linked polymer networks) may have a certain molecular structure,or may be seeded by such a material, that causes a reduction ofviscosity of the material (making them more flowable) when under theapplication of shear forces. This reduction in viscosity may bereversible or irreversible. The reversing mechanism can be automatic orby way of an external trigger or chemical reaction. If the reduction ofviscosity is reversible, the reversing time may be adjustable to allowfor the time required for filling the teeth.

In some arrangements, shear-thinning behavior can usually be observedwhen in the presence of various configurations, such as a solution oflong chain polymers or a cross-linked polymer (e.g. short chain)network. When in the presence of long chain polymers, the molecularnetwork of the obturation material can be subjected to a shear flow thatcan evolve from an entangled state to a more structured orientation thatfollows the main direction of the flow. The alignment can reduce theapparent resistance of the fluid to the driving force (e.g., can exhibitlower viscosity) due to the untangling of the polymer molecules. Thefluid may therefore exhibit shear thinning behavior. When the amount ofstrain applied to the fluid is sufficient, the change in the fluidproperties can be reversible. The relaxation time of the molecules maydrive the time it takes for the fluid to go back to its original state.

When in the presence of a cross-linked polymer network, each polymermolecule of the obturation material can be linked to its neighboringmolecules (e.g., by cross-linking, typically covalent or ionic bonds).When subjected to a shear flow, the links between the molecules may bebroken and the polymer molecules can move “freely” into solution, henceleading to a lower apparent viscosity. If the links can be reformed(e.g., via heat, pH, etc. . . . ), the process may be reversible. If thenetwork cannot be reformed, the process may be irreversible.

When subjected to a large enough deformation, polymer molecules of theobturation material may break. The breakage may lead to a drop inapparent viscosity (shear thinning). Such large-deformation processesmay be irreversible.

IV. Examples of Test Results

FIG. 9A is a photograph illustrating a top cross-sectional view ofobturated root canals 913 of a tooth 910 that was filled in a procedurein accordance with various embodiments disclosed herein. As shown inFIG. 9A, a narrow isthmus 914 (e.g., which may be as narrow as about10-20 microns) can connect the canals 913. It should be appreciated thatother obturation procedures may not be able to effectively fill suchnarrow, irregular and complex isthmuses 914. FIG. 9B is a scanningelectron micrograph of a split, obturated root that was filled in theprocedure of FIG. 9A. The root canals 913 in the test of FIGS. 9A-9B wasfilled using a treatment handpiece similar to those disclosed in FIGS.4A-8D. In FIG. 9B, the tooth 910 (e.g., walls of the canals 913) areshown at the bottom of the image, and the obturation material 901 isshown at the top of the image. For the test conducted in accordance withFIGS. 9A-9B, the obturation material comprised a catalytically curableresin-based material delivered using a handpiece comprising a liquid jetdevice.

In this example, a filling material composition, referred to as a baseresin, was prepared by combining 49 parts by weight of 2-hydroxyethylmethacrylate, 43 parts by weight of poly(ethylene glycol)dimethacrylate, 5 parts by weight of triethyleneglycol dimethacrylate,and 5 parts by weight of N,N-di(hydroxyethyl)-p-toluidine. The mixturewas degassed prior to being delivered to the root canal. A separatecatalyst resin mixture was prepared by combining 19 parts by weight ofpoly(ethylene glycol) dimethacrylate and 1 part by weight of dibenzoylperoxide. Extracted human molars were prepared with an endodontic accessopening and the root canal systems were cleaned using a handpiece with aliquid jet device. The base resin was delivered into the root canalsystem by way of the jet device, e.g., the base resin was routed througha small orifice at a proximal portion of a guide tube. The stream ofbase resin material was delivered within the root canal system.Subsequently, a small volume (about the same or less than the volume ofbase resin within the root canal system) of the catalyst resin wasinjected through the endodontic access opening into the pulp chamber bysyringe, followed by additional delivery of base resin via the jetdevice. The combined composition hardened within less than about 3minutes throughout the entire root canal system.

In the test associated with FIGS. 9A-9B, the root canals 913 andisthmuses 914 were fully filled with obturation material 901. Theobturation material 901 was uniformly hardened and void-free throughoutthe entire canal system. As shown in FIG. 9B, the sectioned, obturatedroots were further examined using scanning electron microscopy imaging,which reveals the obturation material filling several micrometers intodentinal tubules. The sample was desiccated prior to imaging, whichcaused the material filling the tubules to be removed from the tubules.The imaged strings 903 shown in FIG. 9B represent the filling material901 that filled the tubules and small spaces of the tooth. Thus, asshown in FIGS. 9A-9B, the pressure wave generator 5 disclosed herein caneffectively and fully fill a root canal system of a tooth, includingsmall spaces in the tooth such as dentinal tubules.

Reference throughout this specification to “some embodiments” or “anembodiment” means that a particular feature, structure, element, act, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, appearances of the phrases “in someembodiments” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodimentand may refer to one or more of the same or different embodiments.Furthermore, the particular features, structures, elements, acts, orcharacteristics may be combined in any suitable manner (includingdifferently than shown or described) in other embodiments. Further, invarious embodiments, features, structures, elements, acts, orcharacteristics can be combined, merged, rearranged, reordered, or leftout altogether. Thus, no single feature, structure, element, act, orcharacteristic or group of features, structures, elements, acts, orcharacteristics is necessary or required for each embodiment. Allpossible combinations and subcombinations are intended to fall withinthe scope of this disclosure.

As used in this application, the terms “comprising,” “including,”“having,” and the like are synonymous and are used inclusively, in anopen-ended fashion, and do not exclude additional elements, features,acts, operations, and so forth. Also, the term “or” is used in itsinclusive sense (and not in its exclusive sense) so that when used, forexample, to connect a list of elements, the term “or” means one, some,or all of the elements in the list.

Similarly, it should be appreciated that in the above description ofembodiments, various features are sometimes grouped together in a singleembodiment, figure, or description thereof for the purpose ofstreamlining the disclosure and aiding in the understanding of one ormore of the various inventive aspects. This method of disclosure,however, is not to be interpreted as reflecting an intention that anyclaim require more features than are expressly recited in that claim.Rather, inventive aspects lie in a combination of fewer than allfeatures of any single foregoing disclosed embodiment.

The foregoing description sets forth various example embodiments andother illustrative, but non-limiting, embodiments of the inventionsdisclosed herein. The description provides details regardingcombinations, modes, and uses of the disclosed inventions. Othervariations, combinations, modifications, equivalents, modes, uses,implementations, and/or applications of the disclosed features andaspects of the embodiments are also within the scope of this disclosure,including those that become apparent to those of skill in the art uponreading this specification. Additionally, certain objects and advantagesof the inventions are described herein. It is to be understood that notnecessarily all such objects or advantages may be achieved in anyparticular embodiment. Thus, for example, those skilled in the art willrecognize that the inventions may be embodied or carried out in a mannerthat achieves or optimizes one advantage or group of advantages astaught herein without necessarily achieving other objects or advantagesas may be taught or suggested herein. Also, in any method or processdisclosed herein, the acts or operations making up the method or processmay be performed in any suitable sequence and are not necessarilylimited to any particular disclosed sequence.

1. A dental apparatus comprising: a pressure wave generator to bedisposed at a treatment region of a tooth, the pressure wave generatorcomprising an opening to deliver a flowable filling material to thetreatment region; and a reservoir for supplying the filling material tothe pressure wave generator, wherein the pressure wave generator isconfigured to generate pressure waves through the treatment region tocause the filling material to substantially fill the treatment region.2. The apparatus of claim 1, wherein the pressure wave generatorcomprises a liquid jet device.
 3. The apparatus of claim 2, wherein theliquid jet device comprises a guide tube, the opening disposed near adistal portion of the guide tube.
 4. The apparatus of claim 1, furthercomprising a cap near the pressure wave generator, the cap at leastpartially defining a chamber, the cap configured to retain fluid in thechamber when the cap is positioned against the treatment region.
 5. Theapparatus of claim 1, further comprising a handpiece, the pressure wavegenerator coupled to or formed with the handpiece.
 6. The apparatus ofclaim 5, wherein the reservoir is disposed in or on the handpiece. 7.The apparatus of claim 6, wherein the reservoir is removable from thehandpiece.
 8. The apparatus of claim 5, wherein the pressure wavegenerator comprises a filling mode in which the pressure wave generatorfills the treatment region and a cleaning mode in which the pressurewave generator cleans the treatment region.
 9. The apparatus of claim 8,wherein the handpiece comprises a switch to switch between the fillingmode and the cleaning mode.
 10. The apparatus of claim 5, furthercomprising a console in fluid communication with the handpiece, theconsole configured to control the operation of a treatment procedure.11. The apparatus of claim 10, wherein the reservoir is disposed in oron the console.
 12. The apparatus of claim 10, wherein the consolecomprises a controller configured to switch between a filling mode and acleaning mode.
 13. The apparatus of claim 1, further comprising thefilling material.
 14. The apparatus of claim 1, wherein the pressurewave generator is further configured to deliver cleaning fluid throughthe opening and to generate pressure waves through the treatment regionto cause the cleaning fluid to substantially clean the treatment region.15. The apparatus of claim 5, further comprising an interface memberconfigured to couple to a conduit in fluid communication with a console,the handpiece configured to removably engage with a distal portion ofthe interface member.
 16. The apparatus of claim 15, further comprisinga cartridge configured to couple with the distal portion of theinterface member, the handpiece configured to removably engage with adistal portion of the cartridge, the cartridge comprising the reservoir.17. The apparatus of claim 16, wherein the cartridge is configured toremovably engage with the interface member.
 18. The apparatus of claim16, wherein the cartridge comprises a first supply line to deliver acleaning fluid and a second supply line to deliver a filling material,the cartridge comprising a switch to switch between the first and secondsupply lines.
 19. The apparatus of claim 16, wherein the cartridgecomprises a supply line, the supply line coiled within the cartridge.20.-34. (canceled)